Dynamics Magazine 1201
64
ISSUE 12.01 ELECTRONICS DESIGN Pushing the Boundaries InDesA Virtual Test Center FEATURES CHASING THE WIND America’s Cup Design LEARJET 60 Designing a Drag-Free Locker RISE OF THE ELECTRIC MACHINE RISE OF THE ELECTRIC MACHINE DYNAMICS ISSUE 12.01
description
Rise of the Electric Machine - Issue 1201 Dynamics is the world's leading CFD online magazine for engineering simulation. The cost of energy has always motivated the development of electric machine design, but today the twin monsters of unbridled consumer demand and scarcity of required materials makes it ever more important to optimize designs with better analytical tools. CD-adapco is the world's largest independent CFD-focused provider of engineering simulation software, support and services and has over 25 years expertise in engineering, employs over 550 talented individuals, working at 21 offices around the globe.
Transcript of Dynamics Magazine 1201
issue 12.01
ELECTRONICS DESIGNPushing the Boundaries
InDesA Virtual Test Center
Features
CHASING THE WINDAmerica’s Cup Design
LEARJET 60Designing a Drag-Free Locker
rise oF the electric machine
rise o
F the e
lectric
machin
edynam
ics is
sue 12
.01
IntroductIon 03 cd-adapco Meets the Electric Machine Introduction by Tim Miller
05 Breaking news •STAR-Cast •DARS •STAR-CCM+v6.06 •NewOffices •STAR-CDandES-ICEv4.16 •PantherRacing •OlinCollegeHPV •PaceFormulaOne
ELEctrIc MAcHInES 1 1 A new, Groundbreaking tool to Simulate Batteries InterviewwithSteveHartridge
13 Electromagnetic capabilities BreakingNewGroundwithSTAR-CCM+
17 rise of the (Electric) Machines: CD-adapco&theNeedforSPEED
ELEctronIcS 19 Pushing the Boundaries ElectronicsDesign
23 Is your Electronics cooling Software Fit for Purpose? ElectronicsCooling
AutoMotIVE 27 Virtual testing InDesAVirtualTestFacilityCenter
31 Sunroof Buffeting ANewFluid-StructureIntegratedCapabilityforAeroacousticsSimulations
35 cFd Helps to Make Engines More Efficient CombustionSimulationswithSTAR-CD
turBoMAcHInErY 37 turbocharger Analysis Thermo-Fluid-StructuralSolutionsusingSTAR-CCM+
39 nASA c3X turbine PolyhedralMeshing&TransitionModeling
41 Harmonic Balance Method ABreakFromTraditionalSimulationofTurbomachineryFlows
AEroSPAcE 43 designing a drag-Free Storage Locker for the Learjet 60 RaisbeckEngineeringshowcasetheirin-houseCFDcapability
47 From design challenge to Flying uAV’s in Fifteen Weeks UniversityofWashington’sCapstoneProject
oIL And GAS 51 deepwater Flow Assurance Integrationof1D&3DFlowSimulation
MArInE 55 chasing the Wind TheNewState-of-the-ArtintheAmerica’sCupDesign
rEGuLArS 59 DrMesh 61 •Training •GlobalEvents
ReselleRs
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south Africa Aerotherm Computational Dynamics [email protected]
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Contents
ReCYCleD pApeR. VeGeTAble INKs.
08 1 1
13 17
23 27
31 37
43 47
Follow us online.
..::INTRODUCTION Tim Miller
i FOR MORe inFORMATiOn eMAiL: [email protected]
The electrification of the industrialized world is accelerating. The number of electric motors used in a single house may easily exceed 50. Count them in your own house. if you find fewer than 10, you haven’t looked hard enough. Similarly
automobiles, aircraft, railway locomotives and all forms of special vehicles rely on more and more electric motors for auxiliary functions and traction. And in factories and offices the motor population is gigantic. Unless you are reading this out in the woods somewhere, you can probably hear an electric motor right now (or more likely, the fan or compressor it is driving).
By far the greatest number of electric motors are the AC induction motor and the DC commutator motor. There are also some specialty motors such as brushless permanent-magnet motors used in a wide range of applications such as small fans and industrial motion control. Highly-publicized electric and hybrid vehicles often use this type of machine, although this could change quickly and dramatically because of rapid increases in magnet costs. electric vehicles account for an insignificant proportion of energy usage, and it is important not to be carried away by the glitzy advertising: most of the world’s electrical energy is used up in those lowly workhorse applications, not in the dream cars of the future.
The cost of energy has always motivated the development of electric machine design, but today the twin monsters of unbridled consumer demand and scarcity of required materials makes it ever more important to optimize designs with better analytical tools. The SPeeD software recently purchased by CD-adapco has been in the business of electric
machine design for a quarter of a century, and is used in thousands of products. Based on the deep underlying theory of the electrical machine, it calculates almost all aspects of design in a highly efficient way. Because of its speed of execution there is practically no waiting time for the designer, a critical requirement in assuring design productivity.
SPeeD is capable of contributing geometry and heat loads to STAR-CCM+ for more intense analysis of heat transfer and fluid flow. eventually there may be a capability for electromagnetic calculations that would extend SPeeD’s accuracy in dealing with three-dimensional effects and eddy-current effects that cause parasitic losses. in the next few months it will be interesting to see how this develops. But however it turns out, CD-adapco has certainly come face to face with the electrical world.
Tim MillerConsultant to CD-adapco, SPeeD & STAR-CCM+Design of electrical Machines
CD-adapco meets the electric machineIntroduction by Tim miller
The cost of energy has always motivated the development of electric machine design, but today the twin monsters of unbridled consumer demand and scarcity of required materials makes it ever more important to optimize designs with better analytical tools.
Civi l izat ion as we know i t is ut terly dependent on electr ici ty, most of which is generated in thermal power stat ions by large rotat ing machines. About 60% of al l electr ic energy is used in electr ic motors driving pumps, fans, and compressors not seen by the general publ ic. Without them we would have no water and no waste treatment. No machinery, no clothing, no transport , and no food. Without electr ic generators and motors, we would be set back to the 19th century.
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..::INTRODUCTION Breaking news
dynamics I S S U E 1 2 . 0 105
digAnarS is pleased to announce the launching of dArS v2.06, the latest release of their advanced simulation tool for the analysis of complex chemical reactions. the latest version includes an improved user interface, significantly reduced
simulation times and improved predictive capabilities.
“FromtheverybeginningourintentionwastomakeDARStheeasiestandmostaccessiblesimulationtoolforunderstandingandoptimizingdevicesthatfeaturecomplexchemical reactions.With the releaseofDARSv2.06wehavefinallyrealizedthatambition”saysFabianMauss,PresidentandFounderofDigAnaRS.“DARS v2.06 provides users from the automotive, energy and chemicalindustrieswithanintuitiveandflexibleanalytictoolkitrequiredtodevelopmoreenvironmentallyconsiderateproductsinlesstimethaneverbefore.”
DARSv2.06setsnewstandardsinthemodelingcatalyticconverters,includingparticulatefilters.CombinedwiththepredictivereactorandenginemodelsDARSv2.06alsoenablestheoptimizationofprocesses.Kineticmappinggivesusersinsightintohowprocessparametersinfluenceprocessefficiencyandemission.DARSprovidesyouthetoolsthatexplainyourresultstoyourcolleagues.
DARS2.06wasofficially launchedat theSTAREuropeanConference2011,presentations and demonstrations that explore all of the new features areavailable.
dArS V2.06 is now available for cd-adapco customers to use.
i FOR MORe inFORMATiOn: www.diganars.com
cd-adapco and Access are pleased to announce the release of an exciting new version of StAr-cast, the technology-leading simulation tool for all industrial casting simulations. developed in collaboration between a world-leading provider of engineering
simulation technology and recognized international experts in casting and metallurgy, StAr-cast v1.10 brings automation and ease-of-use into casting and foundry processes.
STAR-Cast provides a comprehensive and intuitive process for performingmultiphasecastingsimulation–liquid,solidandgaseous–includingconjugateheattransfer,asharpresolutionofthefillingfront,free-surfacefragmentation,motionoftrappedgasbubblesinmelt,andnaturalconvectioninmeltandgas.“STAR-Cast v1.10 includes a new streamlined casting simulation process that places industrial strength simulation technology in the hands of foundrymen, casting designers and tool makers,”saysRobertGuntlin,ManagingDirectorofAccess.“The addition of new tools that facilitate High Pressure Die Casting and Investment Casting makes STAR-Cast v1.10 a formidable tool that I sincerely believe will lead to unprecedented levels of innovation and cost reduction in industrial casting.”
“CD-adapco is committed to making the best advanced engineering simulation technology available for solving the most difficult problems that manufacturing has to offer,”saidCD-adapcoPresidentSteveMacDonald.“STAR-Cast v1.10 is a product of our many years of simulation experience combined with the leading expertise of Acces in casting and metallurgy. We are proud to be their partners.”
StAr-cast v1.10 is now also available on the Windows 7.0 platform. Enhancements to StAr-cast v1.10 include: High Pressure die casting:STAR-Castv1.10includestheabilitytosimulatethe action of a moving piston, facilitating the analysis of High Pressure DieCasting(HPDC)processes.
Shell Molds for Investment casting: Realistic modeling of dipping-typeceramic shell molds is crucial to accurate simulation of investment castingprocesses.STAR-Castv1.10providesahigh-performancetoolforcalculatingtheoutersurfaceofthevirtualshellinclosecorrelationtotherealshapeofthemold.
Investment casting Misrun Prediction: ThepredictionofmisrunformationisbasedonSTAR-Cast’sunique,fullycoupledcomputationalcontinuummechanicsapproach,featuringamultiphasemoldfillingmodule.
Material database: Theprecisionofcastingsimulationresultsdependstoahighdegreeonthequalityandcompletenessoftherequiredmaterialdata.Forthis reason,STAR-Cast offers a dedicatedmaterial database,STAR-Castmat,whosedataarecertifiedandqualifiedaccordingtoaninternaldocumentationscheme.
i ViSiT THe neW STAR-CAST WeBSiTe: www.star-cast.com
www.cd-adapco.com/newsFollowthelatestbreakingnewsonline:
StAr-cASt V1.10:InduStrIAL StrEnGtH cAStInG SIMuLAtIon For FoundrYMEn, dESIGnErS And tooLMAkErS
IntroducInG dArS V2.06: AdVAncEd cHEMIStrY SIMuLAtIon For EFFIcIEnt & GrEEn EnGInEErInG
..::INTRODUCTION Breaking news
dynamics I S S U E 1 2 . 0 1 06
Now Available!
cd-adapco is pleased to announce the release of StAr-ccM+ v6.06, cd-adapco’s simulation software for solving multidisciplinary engineering problems.
“Released three times a year, each new version of STAR-CCM+ isfocused on improving customer satisfaction,”saysSeniorVPofProductManagementJean-ClaudeErcolanelli.“We set ourselvesa very high standard in this regard and our success is confirmedby our users: in our annual 2011 customer survey, 97% ofCD-adapco users said that they would recommend our software.”
StAr-ccM+ v6.06 ensures higher throughput and offers:
FAStErturnaroundtimes:supportofparallelI/Ofilesystems,newsparsesolverforelectricalsolutions,quickerpolyhedralmeshing,andnewCADreadingtechnology;BEttErapplicationcoverage:improvedprocessforLi-ionbatteriessimulation,newphysicalmodelsforEulerianmultiphaseflowandLEScombustion;WIdErmultidisciplinarysolution:simulationofelectromagneticsandelectricalfields,andimportofSPEEDmodelsforflowandthermalanalysesofelectricaldevices.
Improvements to the user EnvironmentOptimizing License Resources: anewflexiblelicensingapproachisadopted,meaningthatuserscantake,reserve,orreleaselicensesforadd-onmodules(suchasBatterySimulationModule,DARS-CFD,JTOpenReader,andCADExchangeReader)fromwithintheirworkingsession.
Geometry Preparation and Surface MeshingCAD Clients:LiveModelCheckerprovidesfeedbackofmodelvalidityduringthesetupprocess,checkingforconsistencyandconflicts.UpfrontflowandthermalsimulationscanalsoberuninparallelfromwithinyourCADenvironment.
Geometry Import:newCADExchangereadersdeliverimprovedreliabilityandspeedwhenreadingnativeCADpartsandassemblies.
Engineering PhysicsSPEED Integration:directlyimportmodelsfromCD-adapco’snewelectricmachinestoolandgeneratea3Danalysis-readySTAR-CCM+model.Thermalfieldscanbetransferredontotheimportedgeometry,allowingfullflowandthermalanalysisoftheelectricaldevice.
Electromagnetics:STAR-CCM+hasanewsolverforMagneticVectorPotential,whichoperatesinstationaryandtransientmodeandcouplestoelectricalpotentialsolverforelectromagneticproblems.Solvercansimulatebothlinearandnon-Linearmaterials.Sample applications: electric motors, alternators, generators,transformers, etc.
Liquid Film:thelatestversioncompletestheSTAR-CCM+liquidfilmcapability,broadeningitsapplicabilityandscope. Anedge-strippingmodelautomaticallyremovesfilmandinjectsdropletswhenasharpedgeisreached.Energytransportisnowpossiblewithinaliquidfilm.Sample applications: vehicle soiling and brake cooling Battery Simulation Module:apipelineprocessallowsbatterysetupmodificationstobeautomaticallyre-executed. STAR-CCM+v6.06alsoallowsarbitrarypolyhedralmeshingforthebatterycellsandforcreatingaconformalmeshbetweenposts,tabs,surroundingfluid,mountings,etc.Anewsparsesolverforelectricalsolutionsisalsoincluded.Togetherthesenewfeaturesprovideasignificantspeedupofsolutiontimes.
For a complete information and exhaustive list of all newfeatures in StAr-ccM+ v6.06 or to download the latest versiontoday please visit cd-adapco’s user services site or contactyour local office.
StAr-ccM+ v6.06:Faster, Better, and Wider
i TRY iT TODAY! www.cd-adapco.com/products/star_ccm_plus
ABoVEVehiclesoilingsimulationusingliquidfilmstripping
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..::INTRODUCTION Breaking news
dynamics I S S U E 1 2 . 0 1
www.cd-adapco.com/newsFollowthelatestbreakingnewsonline:
After years of its office location in tustin, cd-adapco is pleased to announce the opening of its new Socal office. Located in Irvine, california, the new, larger facility is specifically designed with customer interaction and future growth in mind.
Due to its growth, CD-adapco relocated its Southern California office to alargerspaceinIrvineattheendofFebruary.ThenewCD-adapcoIrvineofficeis centrally locatedbetweenSanDiegoand LosAngeles. Theoffice spacewentfromasmallsuiteoflessthan1,000squarefeetinTustintoa6,376squarefootofficeintheIrvineTechnologyCenter.Thislocationprovidesstate-of-the-artcomputingfacilitiesanddedicatedcustomerareasfortrainingandconsultancytechnologytransfer.Inaddition,theofficefeaturescontemporaryarchitectureandattractivelandscaping.TheIrvineTechnologyCenteriseasilyaccessiblebymajorfreeways,I-5andI-405.
Cyndi Taylor, CD-adapco’sWorldwide FacilitiesDirector commentedon themove,“The office team is truly happy to have completed the move. We are not using all the space now but we have planned for future growth in the Southern California area.”Taylorcontinued,“In this move, we increased our fiber optic bandwidth to support larger projects and increase our customer satisfaction of our sales and support teams. We have always worked hard to make visitors to our offices feel welcome. The new office space allows us to do that. We are all looking forward to welcoming new and current customers and associates to join us in the Southern California CD-adapco office.”
cd-adapco Los Angeles, 1 technology dr. Suite #I825, Irvine, cA 92618-2319tel: (+1) 949 398 8330 Fax: (+1) 949 398 8332Email: [email protected] Support: [email protected]
i GLOBAL LOCATiOnS: www.cd-adapco.com/about/locations
cd-AdAPco AnnouncES tHE oPEnInG oF ItS nEWSoutHErn cALIFornIA oFFIcE
cd-adapco has a new office location in the detroit, Michigan area. cd-adapco’s Plymouth, Michigan office has recently moved to a new spacious and modern office in northville, Michigan. the new office is designed with client interaction in
mind, with a state-ofthe-art training facility, and dedicated desk space at which customers can work alongside cd-adapco engineers when visiting the office.
Thenewbuildingalsoincludesanexpandabledatacenter,allowingCD-adapcotogrowitscomputingresourcesasquicklyasitgrowsitscustomerbase.
TheDetroitteamisveryproudoftheirnewofficeandtheyareexcitedtoshowitoff.ThebeautifulNorthvillelocationisconvenientlylocatedjustoffhighwayI-275,taketheEightMileexitandtravelwestoneblocktoHaggertyRoad.CD-adapcoisinthe“FarmingtonHillsCorporateCenterI”complexat21800Haggerty Road, Suite 300 on the 3rd floor. The office phone number haschangedto248-277-4600.CD-adapcoispleasedtoinviteyoutovisitthenewofficewheneveryouareintheDetroit,Michiganarea.
cd-adapco detroit, Michigan, 21800 Haggerty road, Suite 300, northville, MI 48167tel: (+1) 949 398 8330 Fax: (+1) 949 398 8332Email: [email protected] Support: [email protected]
cd-AdAPco AnnouncES tHE oPEnInG oF ItS nEWdEtroIt oFFIcE
cd-adapco is pleased to announce the release of StAr-cd andes-ice v4.16, the latest version of its comprehensive toolkit forengine simulation. cd-adapco’s purpose is to help customers suceed through the application of engineering simulation:
driving innovation in its products And reducing the time and cost associated with bringing those products to market.
STAR-CD increases the potential for innovation through the addition andimprovementofphysicalmodelingcapabilities,andreducethetimeandcostofsimulationwiththeintroductionofpowerfulnewautomationcapabilities.
Physical modeling capabilities• Further improvementandnewoptionsandcapabilitiesfortheG-equation combustionmodel• NewactivemodeoptionforDARS-KnockforbothECFM-3ZandG-Equation• Further validation and consolidation of other existing ICE related spray, combustionandemissionmodels.
Improved mesh qualityOngoing improvements to trimming, smoothing and prism layer technologyleadingtobetterqualitymeshesandincreasedsolverrobustness.Betterqualityprism layermeshing next to walls. Localmesh refinement for trimmed ICEmeshes.
AutomationOngoingimprovementsto2Dtemplategenerationaswellas2Duniformityandlocalmeshrefinementinstrategicareasoftheenginetofurtherhelpease-of-useandmeshquality.Automaticvalvefeaturecapturing.
Mesh replacement and solution mapping for moving mesh IcE applicationsFurtherenhancedwithmorestreamlinedandclearsetupprocess,making iteasiertouseandlesspronetomistakes.Themesh-to-meshmappingcapabilitynowcoversallICErelatedcombustionandemissioncapabilitiesandhasalsobeenimprovedforfurthermappingaccuracy.
Improved documentationNewBestPracticesdocumenttohelpsetupandrunICEsimulations.Setofnewtutorialscoveringmoreadvancedmultiplecycleandcylindersimulations.
try it out today!
StAr-cd And ES-IcE V4.16: LAtESt VErSIon oF SIMuLAtIon tooLkIt rELEASEd
i FOR MORe inFORMATiOn: www.cd-adapco.com/products/star_cd
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..::INTRODUCTION Breaking news
dynamics I S S U E 1 2 . 0 1 08
Panther racing demonstrates StAr-ccM+ Simulation Leads to Engineering Success
StAr-ccM+ simulation software aided with designing the Panther racing team’s Indycar which Jr Hildebrand drove to second place at the Indy 500.
CD-adapcowouldliketocongratulatethePantherRacingTeamandJRHildebrandontheirsecondplacefinishintheGreatestSpectacleinRacing:theIndianapolis500. Panther Racing uses CD-adapco’s STAR-CCM+ engineering simulationsoftwaretooptimizetheaerodynamicperformanceandthermaldurabilityofitsIndyCar to gain a competitive advantage.Given thatHildebrandwas also thefastestrookieinthefield,itwouldappearthattheengineersatPantherRacinghavecapitalizedonthisadvantage.
The Panther Racing National Guard IndyCar, piloted by 23-year-old rookie JRHildebrand,wasdeniedvictoryinperhapsthemostdramaticfinaleinthe100yearhistoryoftheworld’sfamousmotor-race.Retakingtheleadlateintherace,Hildebrand needed to round the final turn and negotiate traffic to secure hisplaceinracinghistory.Unfortunately,Hildebrand’stireslosttractionon“marbles”(lumpsofdiscardedtirerubber),losingtractionandcausinghimtocrashintothewallofTurn4andyieldvictorytoDanWheldon.Despitethedamage,HildebrandwasabletohangonforanothersecondplacefinishforPantherRacingmakingthis4inarow.
“The disappointment of not winning the race isn’t for me personally, but more for my team, Panther Racing and for everybody in the National Guard,”Hildebrandsaid. “These guys did an unbelievable job putting us in a position to win the Indianapolis 500 and I don’t think you can say enough about our performance here this month.”
CD-adapco’sSeniorVP,BillClark,wasimpressedbyHildebrand’sperformanceonthetrackbutmoresobyHildebrand’sattitudeimmediatelyfollowingtherace:“Our company’s success is heavily dependent on team work and each employee’s desire and commitment to pursue excellence. The poise and humility that Hildebrand exhibited in the moments after the race are a credit to his character and demonstrate his reliance on and respect for his Panther Racing teammates. CD-adapco is proud to have played a small part in this inspirational story. We are confident that Panther Racing will return to the victory lane soon.”
i FOR MORe inFORMATiOn On PAnTHeR RACinG, PLeASe ViSiT: www.pantherracing.com
97% of customers would recommend cd-adapco,says surveyconducted during February and March 2011, cd-adapco’s annual customer satisfaction survey elicited aresponse from 11% of cd-adapco’s 8000 strong user base, including both software and services customers,from across industry and academia.
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..::INTRODUCTION Breaking news
dynamics I S S U E 1 2 . 0 1
www.cd-adapco.com/newsFollowthelatestbreakingnewsonline:
the olin college Human Powered Vehicle team recently participated in ASME’s Human Powered Vehicle competition (East) at the Indianapolis Motor Speedway and with the help of StAr-ccM+, finished first place in all categories.
CD-adapco has been a longtime supporter of academia in both teaching andresearchendeavors.Notonlydoes itoffer licensestoacademiaatdramaticallyreduced pricing, but it donates STAR-CCM+ to any academic team that canbenefitfromCAEsimulation.TeamshaveincludedFormulaSAE,HumanPoweredSubmarine, Baja Racing, ecoCARChallenge, Eco-Marathon and as seen here,HumanPoweredVehicle.
Theteamplacedfirstinallcategories:firstoverall,firstindesignreport,firstinmalesprint (38mph),first in femalesprint (30mph)andfirst in thesprintenduranceevent. The design of a more aerodynamics shell gave Olin College a greatadvantage.“We finished first place in all categories and a large part of our success
can be attributed to a well-designed fairing coming from using STAR-CCM+ for analysis,”saidAlexNiswander,TeamLead,OlinCollege.
About olin college Human Powered Vehicle teamThe American Society of Mechanical Engineers (ASME) sponsors the HumanPowered Vehicle Challenge. Each year, teams from colleges across the nationdesign,build,andraceavehicleinoneoftwocategories:speedorunrestricted.OlinCollegehasparticipatedinthespeedclasssince2007.Speedclassvehiclesaretypicallyfullyfairedbicycles,andarejudgedbasedonatechnicaldesignreport,asprintcompetition,andanendurancecompetition.Initsshorthistory,Olinhashadaverysuccessfulshowingatcompetition.ThispastyearOlinsweptthespeedclasstaking1stineveryevent.
oLIn coLLEGE HuMAn PoWErEd VEHIcLE tEAM uSES StAr-ccM+ And WInS ASME’S EASt coASt coMPEtItIon
A team of mechanical engineering students from Brigham Young university won the Best Paper/Presentation Award at the PAcE Forum hosted by the university of British columbia in Vancouver, British columbia, canada, July 27-29, 2011. Led by Professors
Greg Jensen and Steven Gorrell, Satyan chandra and Allison Lee worked on the project.
AspartofthePACEprogram,theFormula1carwasdevelopedinacollaborativeeffort between 26 different universities in 10 countries. Several companies,includingGM,Siemens andHPwere also part of the consortium. This projectfocused on using Computational FluidDynamics (CFD) to understand how theFormula1carwouldbehaveduringhighspeedmaneuvers, inorder toensurestabilityatspeedsexceeding200milesperhour.“There is nothing that has wowed me more than cars and airplanes,” commentedChandra.“I love cars, and am very passionate about Automotive Engineering. I taught myself to drive in the 4th grade, and have a professional racing license. Naturally, this project was very appealing to me!”
Chandra,originallyfromIndia,workedwithAllisonLee,aseniorfromMesa,AZ,to learn how to use STAR-CCM+, perform the simulations and analysis, writethepaper,andorganizethepresentation.“It was a comprehensive research and development effort,”saidChandra.“The focus was first to obtain accurate and highly representative aerodynamic representations of the car, optimize the design of the front and rear wings, and then work on the presentation and the paper for the conference and hopefully later publication.”TheresearchalsoinvolvedworkingwithengineersfromCD-adapco.
TheprojectcameawayfromthePACEForumwiththeBestPaper/Presentationaward. Dr. Jensen presented the paper, which was an analytical study on airfloweffectsandresultingdynamicsonthePACEFormula1racecar.Thestudyincorporated Computational Fluid Dynamic (CFD) analysis and simulation tomaximizedownforceandminimizedragduringhighspeedmaneuversoftheracecar.UsingSTAR-CCM+andmentoringprovidedbyDr.LorenzoCrosatti,applicationengineerfromCD-adapco,thesimulationemployedefficientmeshingtechniquesandrealisticloadingconditionsinordertounderstanddownforceonfrontandrearwingportionsofthecaraswellasdragcreatedbyallexteriorsurfaces.Thestudyalsoensuredsafetyofoperationandallowedforoptimizationofperformanceforracingconditions.
“This particular CFD project spanned eight months and included students, professors, and industry representatives,” stated Chandra. “We spent lots of late nights, with lots of troubleshooting and overcoming difficulties. It was truly a challenge with the sheer complexity of it. But there was nothing I would have rather done.”
BESt PAPE r/PrESEntAtIon AWArd For PAcE ForMuLA 1 cAr cFd ProJEct
i MORe inFORMATiOn: hpv.olin.edu/
i MORe inFORMATiOn: me.byu.edu/
see first hand how Raytheon is tackling thermal management problems using sTAR-CCm+ on-Demand Recording Now Available: www.cd-adapco.com/ec01
eNGINeeRING sImUlATIoN FoR A FUll RANGe oF eNVIRoNmeNTAl CoNDITIoNs
sTAR-CCm+: poWeR with easeoptimal Thermal management in electronic systems Design
Delivering the power of integrated fluid dynamics & heat transfer simulation technology
with the ease of modeling real & complex geometries
Follow us online. www.cd-adapco.com/products/sTAR-CCm_plus
For more information: [email protected]
A New, Groundbreaking Tool tosimulate batteriesInterview with steve Hartridge, Director, electric & Hybrid Vehicles on CD-adapco’s uniquesimulation tool for the design and analysis of li-ion batteries
1 1
..::FEATURE ARTICLE Batteries
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Timeline of BaTTery HisTory
“Battery”
Americanstatesmanandinventor,BenjaminFranklin
coinedtheterm“battery”whenheusedittodescribean
arrayofLeydenjarsbyanalogytoanartillerybattery.
Voltaic Pile
Italianscientist,AlessandroVoltadiscoveredthefirstpractical
methodofgeneratingelectricityandinventedtheVoltaicPile,
thefirst“wetcellbattery”thatproducedareliable,steady
currentofelectricity.
daniell cell
Englishman,JohnF.DaniellinventedtheDaniellCell,an
improvedversionoftheVoltacell,whichwasusedinhomes
forover100yearstopowerobjectssuchastelegraphs,
telephones,anddoorbells.
Fuel cell
Welshjudgeandphysicalscientist,WilliamRobertGrove
developedthefirstfuelcell.
rechargeable
Frenchinventor,GastonPlantedevelopedthefirstpractical
storagelead-acidbatterythatcouldberecharged.Thistypeof
batteryisprimarilyusedincarstoday.
dry cell
Frenchengineer,GeorgesLeclanchédevelopedatransportable
carbon-zincdrycell,alsocalledtheLeclanchécell.
Alkaline Storage
Americaninventor,ThomasEdisoninventedthealkaline
storagebattery.
Solar cells
Americamresearchers,GeraldPearson,CalvinFullerand
DarylChapininventedthefirstsolarbattery.
Lithium-ion Battery
Japanesechemist,AkiraYoshinoinventedtheLi-ionbattery
underitscurrentform.Itwassubsequentlycommercialized
in1991bySonyandAsahiKasei.
❐ TRIVIA
1748
1800
1836
1839
1859
1866
1901
1954
1985
ABoVEBatterypackmodeledinSTAR-CCM+
one year after the StAr-ccM+ Battery Simulation Module (BSM) was first released, we meet with Steve Hartridge, director, Electric & Hybrid Vehicles at cd-adapco, for an update on this unique battery technology. could you please describe the product in a few words Ofcourse.IncollaborationwithBatteryDesignLLC,wehavedevelopedauniqueworkingmethodologyfortheanalysisofelectrochemicalandthermalperformanceoflithium-ionbatterycells,modulesandpackinstallations.
Who is this product intended for? Asyoucanimagine,moreorlesseverymajorplayerintheautomotiveindustryis interested in the electrification of the powertrain and related issues. Theyareawareof thevalueofnumeric functionalassuranceandofCFDsimulationmethods.Inthefieldofelectricvehicles,newapplicationareasareopeningup.For example, the positioning of the battery in the vehiclemust be studied indetailtoavoidthenegativeimpactofapoorlyinstalledbatterypack. Inaddition,companiesthatpreviouslyhavenotbeenconcernedwithsimulation,suchasbatterymanufacturers,havenowenteredthearena.Forthatfactalone,wearedealingwithagrowingmarket.
What specific expertise does cd-adapco contribute? What do the cooperation partners provide? An important collaboration is with Battery Design LLC, about which anannouncement was made in November 2009. The company, based inCalifornia, has over ten years of experience with the development of lithium-ion battery analysis software and cell design consulting. Together, we provideuserswithacompletesimulationprocess,fromthedefinitionofthebatterycellprototypeornewactivecoatingstothevisualizationoftheirelectrochemicalandthermalperformanceaspartofalargetractionbatterypack. Wealsoworkwithanumberofmajorplayersinthebatteryindustryandresearchinstitutions,suchastheASCS(AutomotiveSimulationCenterStuttgart)andtheUSNationalRenewableEnergyLaboratory.Hereby,processesdevelopedaspartoftheongoingcooperationbetweenCD-adapcoandBatteryDesignLLCareusedandvalidatedinveryrigoroussituations,therebyensuringthatourmethodologyandsolutionsremainstate-of-the-art.
You stated this product is unique. What is unique about it? The detail of the underlying electrochemistry models and the battery cellunderstanding:havingtheabilitytocomputeboththethermalandtheelectrical/electrochemical solution within one code and ensure that all phenomena areincludedtoachievethecorrectoverallperformance.
could you describe the process? Thisnewbattery technologyallows theuser tomigrate fromshort lengthscalesimulations,suchasstudiesofadetailedsinglecell,tocomplexbatterymodules,packs or complete installations, including hundreds of battery cells and theirsurroundingstructureandcoolingsystem.Thesamebatteryperformancemodel,currentlyarangeofthree,canbeusedinanyofthedifferentlengthscalemodels.Thisremovestheneedforduplicatingorsimplifyingtheengineeringtasks,therebyfacilitatingthedivisionoflabor.Oneengineer,probablypartofthecellteam,createsabatterycellmodelandbeginsrunningcelllevelsimulations.Thismodelcanthenbepassedontoanotheranalyst,maybeworkingintheapplicationteam,whousesittocreatecomplexsimulationsofbatterymodulesorpacks.Thisprocessensuresthatthereisnoduplicationinthetwoengineers’timewhileprovidingahighfidelitynumericalmodelandcoupledflow,thermal&electrochemicalsolution.
do such analyses need much cPu time? Thatdepends.Obviouslycertaindetailsrequiredfortheexactmodelingofbatteriesmeanoverheadandthisisreflectedinextendedcomputingtime.Ofcourse,itisalsotruethatCFDandconventionalcalculationmethods,suchasthefinite-volumemethod,alreadydemandmaximumcomputing resources.Someof thebatterymodelswehaveimplementedboastahighperformanceevenonsimpledesktopworkstations: running through the entire process requires only a fewminutes.However,thecomputingtimeisverydependentonthegeometrydetailsandthedesiredqualityofthecalculationresults.
does the grid generation required by such a task pose a particular challenge? STAR-CCM+isaCFDcodeforawiderangeofapplications,andassuchincludesmany state-of-the-art meshing tools. Due to the layout, batteries consist ofrecurringidenticalstructures;cellsthattypicallyoccurbetween30and100times.Forthis,verythinelementsaresometimesusedintheformofplates.AllthesecanbeeasilyinterlinkedwiththemeshingmethodsimplementedinSTAR-CCM+.Iwouldalsoliketoaddthatindependentthermalandelectrochemicalresolutionscanbeused.Typically,thisallowstheusertogetahigheraccuracyoftheflow/thermalresultswhileoptimizingthespeedoftheelectrochemicalsolution.
Are you saying the geometries do not require particular attention? Thegeometrymaywellbecomplex,butwecanhandlethemandhavenoneedtodevelopspecialalgorithmsoradaptexistingones.Besides,notonlycanflatbatterycellsbesimulated,buttheanalysismethodhasbeenextendedtospiralcells,suchascylindricalandprismaticmandrelwoundcelljellyrolls.
What can you tell us about the roadmap for this application? We are moving into the field of electrochemical reaction mechanisms. Wehaveaclearlydefinedrangeoffunctionswithafixedtimetablethatwewanttomake available to our customers. Recently, a 3D electrochemistry solver hasbeencreatedformicroscaleanalyses.Thisdevelopmentextendstheapplicablelength scales of battery simulation to unit cell on amicrostructural level. Themethod removes the macro-homogeneous elements with 1D or pseudo2D electrochemistry models and chooses instead to represent the variousphases within the electrodes as distinct regions: active material, electrolyte,conductivity aid, separator and collector. The geometry is now resolved, andthe simplified fundamental equationshavebeenadded toSTAR-CCM+’ solvercapabilities,therebyenablingthecomputationofthefollowingquantities: -saltconcentrationintheelectrolyteregion; -lithiumconcentrationinthepositiveandnegativeactivematerials; -potentialinboththesolidandelectrolyteregions; -thermalenergywithinalloftheregions. Using this technology, cell designers andmaterial specialists can explore andoptimizeactivematerialpackingratio,particleshapeandsizedistribution,electrolytepropertiesandotheraspectsundervariouschargeanddischargeconditions.ThisisabolddevelopmentwhichCD-adapcoisfirsttobringtomarketandextendsthelengthscalerangetowhichsimulationtechnologycanbeappliedinthisfield.
not everybody is able to operate a cFd code. Will your company support its customers by providing computing services? Certainly! It isnotourstrategytodevelopacertain functionality insecrecyandtoofferitonthenextdayviaourcodetoourcustomers.Wedeveloptechnologyin close collaboration with our customers as part of engineering services. Theunderlying logic is quite clear: themorewework togetherwith customersandtheir internal and external clients, themore developments and technology wecanimplementinlaterreleases,which,inturn,canbemadeavailabletoawideruserbase. <
..::FEATURE ARTICLE Batteries
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i ACCeSS ARTiCLeS, BROCHUReS, FLYeRS, MAGAzineS, WeBinAR ReCORDinGS & MORe: www.cd-adapco.com/downloads
ABoVEScreenrepresentationofthepackwithintheSTAR-CCM+interface
..::FEATURE ARTICLE Electric Machines
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STAR-CCM+ BreaksNew Ground WithElectromagneticCapabilitiesStephen Ferguson - CD-adapco
❐ FACT
CD-adapco Releases SPEED
In June 2011, CD-adapco acquired the electric machine software, SPEED. The
version 2011 release is available with over 350 enhancements. SPEED software
allows users to design electric machines such as induction motors (polyphase/1-
phase); brushless permanent-magnet motors (square wave/sine wave); d.c.
brush motors; switched reluctance motors; and synchronous reluctance motors.
Many of the new features in SPEED are intended for generators as well. With
over 1500 customers using SPEED for over 20 years, they are among the leading
manufacturers, designers, developers and users of electric machines.
..::FEATURE ARTICLE Electric Machines
dynamics I S S U E 1 2 . 0 1 14
This trend is leading to the increasing electrification of vehicles from mild hybrids (storing braking energy in a device), to strong serial hybrids (where the electric motor is permanently connected to the axles), to full electric vehicles (where the only driving force is the electric motor). In all these “hybrid” vehicles, there is the need for a significant electric machine which was not part of the mechanical design or cost structure of previous, older products. As the automotive industry reacts to changing consumer demands, driven in some part by the incentives available from certain governments, they turn to their partners and established suppliers to help find solutions.
With this clear need in mind, CD-adapco, established as the No. 1 independent simulation provider to the automotive industry, has begun a significant development effort to enhance its class-leading simulation tool, STAR-CCM+, to cope with these new demands. The challenge is to provide a process which is easy to use but also powerful enough to capture all the physical phenomena present in an electric motor. The design and simulation problem is made all the more acute as auto manufacturers push components to the edge of their operating envelope in order to outperform each other. To be able to simulate such extreme conditions, a software tool must capture all the relevant physics within one numerical solution and compute results for all mechanisms during this single solution. This objective drives the enhancement of STAR-CCM+ to an ever wider audience, capturing an ever increasing physical spectrum. g
The automotive industry is seeing a dramatic shif t towards fuel eff icient vehicles. This al lows consumers to reduce their personal greenhouse gas emissions and gives them the opportunity to use al ternat ively powered transportat ion.
ABOVEElectric Machines can now be simulatedwith STAR-CCM+
..::FeATURe ARTICleElectricMachines
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www.cd-adapco.comFORMOREINFORMATIONABOUTELECTRICMACHINES,PLEASEVISIT:
Inelectricmotordevelopment,multipleengineersworkingindifferentdisciplinestypicallyhandlethecoupledproblemofelectromagneticallygeneratedthermalanalysis. For example, while engineers with electromagnetic backgroundsevaluatethemotorperformance,thereliabilityisassessedbyadifferentsetofengineerswhouseacombinationofmechanicalandthermaltools.Itisoftenquoted that a sustained 10°C increase in operating temperaturewill reducetheinsulationlifewithinamotorby50%.Thisshowsthevalueofevensmallincremental improvements in amotor design.Moreover, a 50°C increase inwindingtemperaturecanincreasetheelectricalresistanceby20%andthereforeleadtoasignificantincreaseintheI2Rlossesofthesystem.Theseengineering‘rulesofthumb’helpexplainwhymotordesigncompanies
investheavilyinsimulation.Indeed,deployingsimulationintheearlystagesofthedesignprocessensures correct solutionsare chosen, avoidingexpensiveredesignsasthemotornearsproduction.
Toaddressthisneed,CD-adapcoisdevelopingelectromagneticcapabilitiesinSTAR-CCM+.Thiscapability,whencoupledwiththeexistingmodels-namelyfluidflow,heattransferandstructuralmechanics-willenabletheelectromechanical,thermalandstructuralanalysestobecarriedoutfromthesamemodel.Thiswillallowsimulationengineers toaccurately visualize theperformanceofelectricmachinesattheedgeoftheiroperatingenvelopes.Oneexampleofthiscoupledbehaviorisasthetemperaturesofthepermanentmagnetswithintheelectricmachineincreaseduringuse,theirmagneticpropertieschangeandaffecttheoutputofthemotor.Tomaintainthepoweroutput,anincreaseininputcurrentisneeded,whichinturnleadstoafurtherincreaseinthemagnetstemperaturesIfthiscontinues,themagnetscanbepermanentlydamaged,leadingtoaloss
inperformanceoftheelectricmachine.Duetothistemperaturedependence,engineers typically design permanentmagnetmotorswith a specificmagnettemperaturethresholdinmind.Magnetsthatcanoperateathigherthresholds
ABoVEAxialFluxMachine:MagneticVectorPotential
ABoVEVariousElectricMachinesSimulations
ABoVEAxialFluxMachineSimulation
..::FeATURe ARTICleElectricMachines
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aremorecostly, andstrongly impact theoverall costof thedesign. Inordertodeliverthehighestperformanceatthelowestcost,engineersmustcarefullyevaluatethemagnetsoperatingtemperatures.Onceamotordesignhasbeenestablished,STAR-CCM+canbeused to
predict theeffectsof the installationon themotorperformance,andassessthedetaileddesignof thecoolingsystem,whether ituses forcedaircooling,liquidcoolingorsimplynaturalconvectionofairfromthesurfaceofthemotor.Furthermore,ifradiationeffectsaresignificant,thesetoocanbeincludedinthesimulation.Besides electric motors, there is a whole host of applications, such as
inductionheaters,eddycurrentbrakingsystemsandlinearactuators,thatrequireanelectromagneticsolutiontoproperlypredictheattransfer.STAR-CCM+’newcapabilitywillbeabletosimulatesuchdevices.DevelopmentinCD-adapco’sEMAGcodecontinuesatafreneticpaceandthisenhancementofthetoolwillbeavailable,initsinitialform,toconsumerslaterthisyear.<
ABoVEUsingSPEEDasadesigntool
i FOR MORe inFORMATiOn, PLeASe SPeAk TO YOUR CD-adapco RePReSenTATiVe OR ViSiT: www.cd-adapco.com
www.cd-adapco.comFormoreinformationaboutElectricMachines,pleasevisit:
dr. tim Miller, originator of SPEEd and now a consultant to cd-adapco commented, “While this is a great development for SPEEd and all our customers, we’re wasting no time in making a complete new release of all the SPEEd software and its documentation. one compelling reason why we’ve joined forces with cd-adapco is to make SPEEd even better.” Miller continued, “An early sign of SPEEd’s progress is the intense collaboration now underway, to share geometry and other design parameters with StAr-ccM+. Another is the development of a 3d electromagnetic solver in StAr-ccM+. And a third is the intense training activity that SPEEd is running — two or three times the previous level.”
..::FeATURe ARTICle Electric Machines
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i MORE ABOUT ELECTRIC MACHINES: www.cd-adapco.com
SPEEd software, which has been in development for the last 25 years, comprises a client base of over 1000 engineers, including many of the world’s leading manufacturers, designers, developers and users of electric machines. SPEEd allows users to design electric machines such as induction motors (polyphase/1-phase), brushless permanent-magnet motors (square wave/sine wave), d.c. brush motors, switched reluctance motors, and synchronous reluctance motors. Many of the new features in SPEEd are intended for generators as well. Professor Tim Miller, Originator and Director of the SPEED software labs
said,“After25yearsintheUniversityofGlasgow,IamdelightedthatSPEEDisjoiningCD-adapco.ItisaperfectlynaturaltransitionfromoneoftheoldestUKuniversities,withoneofthelongestandrichesthistoriesofacademic/industrialinteractioninengineering.ThecombinationofSPEEDandCD-adapcolaysthefoundationforanewphaseofdevelopmentinsoftwareengineeringservicestomanufacturingcompanies inelectricmachinery, coveringall sectors includingexcitingnewdevelopmentsinpowergenerationandelectric/hybridvehicles,aswellasallourvariedfieldsofactivity.”Hecontinued,“Iampersonallylookingforwardtoarenewalofallaspectsof
SPEED’sservicetothisvitalgroupofindustries,balancingtheneedforcontinuitywiththeneedfordevelopmentandintegrationwithrelateddesigntoolsfromCD-adapcothemselvesandotherswithwhomwehaveworkedformanyyears.ThephilosophyofcustomerservicethroughtheprovisionofleadingenablingdesigntoolsisidenticalinSPEEDandCD-adapco,soIbelievewewillseeavigorousandstimulatingnewera.IamveryproudtobepartofitandIhopeallourcustomerswillstaywithustorealizethefullpotentialofourpartnership.”ProfessorJohnMarsh,HeadoftheSchoolofEngineeringattheUniversityof
Glasgowandinstrumentalinthedeal,added,“Thisisagreatexampleofhowknowledgedevelopedwithintheuniversitycancreateaproductwhichwillhavesignificantvalueforusersinthisfield.WeareveryproudofSPEED’sheritageand
thepositionitholdsinthemarketplaceandarepleasedtoworkwithCD-adapcotoallowittoflourish.”CD-adapco’sPresident,SteveMacDonaldexplained,“SPEEDsoftwaretakes
CD-adapco to the forefront of the electric machine design and is absolutelycomplementary to the ongoing organic developments in-house: specifically,to create a detailed 3D electromagnetic solver which will become part of STAR-CCM+andmovethemarketforwardforelectricmachinesimulation.”MacDonald went on to comment, “These developments mark a significant
commitment fromCD-adapco in theelectromagneticfield, theultimateaim tofurtherstrengthenoursimulationtoolandprovidemoresolutionstoourcustomers.ForustobeaseriousplayerinthisarearequiresexpertiseandoneofthemostrenownedpeoplewalkingonthisplanetintheareaofelectricmotorsisProfessorTimMiller.Wearedelightedtohavejoinedforceswithhim.”<
CD-adapco recently f inal ized the purchase of SPEED, a leading electr ic machines design software tool developed at the Universi ty of Glasgow.
Del ivering on their promise to accelerate the development of the SPEED product, the f irst CD-adapco branded release of SPEED contains over 350 enhancements.
Rise of the (electric) machines: CD-adapco & the Need for speeDscott Del porte - CD-adapco
..::FeATURe ARTICle Electric Machines
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Automotive (Hybrid & Electric Vehicles as well as commercial, Industrial, Agricultural & Mining Special Vehicles) SPEED’sfinite-elementGoFERandembeddedsolvercombinecomprehensiveanalyticalmodelscoveringallaspectsofthedesignofthesemachines,includingthermal,electromagneticanddrivecontrol.Enhancementshavebeenmadeinallaspectsofthedesigncalculationstoimproveaccuracyandcoveranevenwider range ofmachine geometries.Of particular importance is the efficientutilization,andelimination,ofmagnets.TheSPEEDsuiteofprogramsisnowstructuredtogiveseamlessdesigncapabilityover the entire range of permanent-magnet machines and the alternativesincludinghybridcombinations.SPEEDcoverstheentirerangeofpower,voltage,andspeedusedinvehiclesystems.SPEEDplaysakeyrolenotonlyindrivetrainengineering but also in auxiliaries such as starter-generators,many kinds ofpumps,blowers,actuators,andeventheKERSsystemsusedinF1. refrigeration, domestic Appliances & Water Efficiency requirements are driving these industries towards continualtechnological evolution, in a context of extreme cost pressure andmaterialsupply issues. SPEED is used as the main design tool in several leadingcompaniesmanufacturingcompressors,washing-machinedrivemotors,pumpsand fans worldwide. The technology covers inductionmotors (both 1-phaseand3-phase),permanent-magnetbrushlessmotors,andline-startPMmotors.Switchedreluctancemotorsarealsousedinafewkeyapplications.SPEED’sabilitytocharacterizeproductsandnotjustconceptsisoneitsmainassetsinservingthissector.Improvementshavebeenmadeinallprogramsinrelationtomachinegeometry,losscalculations,drivecontrol,andfinite-elementanalysis. Aerospace High power-density, high speed and fault tolerance are key requirements inaerospace.SPEEDhasbeenused formanyapplications includingactuators,pumps,andstarter-generators,andweare“on”someofthemostadvancedelectrically-equippedaircraft.Brushless PM machines and switched reluctance machines are the maintechnologies. Inbothoftheseareas,SPEEDhasnewfeatures improvingtherangeofmachinegeometry,andthecalculationofelectromagneticandthermalperformance. Industrial SPEEDisbehindthedesignofsomeoftheworld’smostefficientACvariable-speeddrives,usingbrushlessSPMandIPMmotorconfigurations.Thecodeisusenotonlyinhigh-efficiencyindustrialdrives,butalsoinprecisionservomotorsystems.We’vemade special efforts to extendSPEED into generators, witha new embedded finite-element solver to cope with a wide variety of loadspecifications,andautomaticcalculationofgeneratorcharacteristicsforwound-fieldsynchronousgenerators.We’veaddedthedoubly-fed inductionmachinetotherange.Improvementsinmachinegeometry,finite-elementanalysis,drivecontrol,andthermalmodelinghavebeenachieved.SPEED’stechnologycoversall kinds of brushless PM machines, synchronous and switched reluctancemachines,inductionmachinesandDCmachines.Axial-fluxmachinescanalsobecalculatedusinganewadditiontotheSPEEDsystem.
The industry highl ights of SPEED’s new features are:
While this is a great development for SPEED and all our customers, we’re wasting no time in making a complete new release of all the SPEED software and its documentation. One compelling reason why we’ve joined forces with CD-adapco is to make SPEED even better.
..::FeATURe ARTICle Electronics
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pushing the boundaries of electronics Designstephen Ferguson - CD-adapco
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..::FeATURe ARTICle Electronics
Whereas previous generations of engineers were able to rely on a combination of engineering intuition and experience to design the cooling of their electronic systems, the ever-increasing,
consumer-led demand for greater performance in a smaller package, means this type of speculative prototyping is no-longer effective. Relianceon intuitiontopredictthecoolingofcomplexsystemsisanalmost
certainguaranteeofbadresults.Notonlyistrial-and-errorprototypingillsuitedfor today’s demandingmarkets, it also fails to derive the full value of designprocesses.Thetimeandcostassociatedwiththisapproachlimitsanengineeringorganization’sopportunitytooptimizedesigns,bylimitingtheresourcesavailabletoexplorealltheideasdesignersmayhave.Thisaffectsproductsbydecreasingprofitmargins, delaying product time tomarket, and increasing product cost.Perhapsmostimportantly,itlimitstheinnovationthatcanbedesignedintotheproductitself. The simple truth is that, in an increasingly competitivemarket place, only
simulation can provide the necessary insight into the performance of a newdevice:“IfIdonotusesimulationandthephysicaltestdoesnotgivemetherightinformationthefirsttime,Idon’tknowhowtocorrectthatsituation,”saidAndrewSlater,DirectorofFlightSciencesatGulfstreamAerospaceCorp.“IfIhavetofixit,Iamveryconstrained,orI’mintoaveryexpensiveprojecttofigureouthowtofixit.ThebenefitofhavingsimulationisthatIgetanindicationofhowtochangetheenvironmentandfixtheparticularproblem.”
Applications Electronicssimulationcantakeplaceonmanylevels;twoofthemostimportantareatthecomponentlevelandthesystemlevel.Components,suchasdiesandheatspreaders,aremadeofawideassortmentofmaterials,fromceramicsandsilicontometalandhybridmaterials.Eachmaterialreactsdifferentlytochangesin temperature,expandingandcontractingatdisparate rates. The interactions
amongthedifferentmaterialscanbecritical.Ifyouhaveacomponentmadeofconflictingmaterials,whereonematerial’svolumegrowssignificantlyasitexpandswithheatandtheother’schangeslittle,thecomponentcanfailasaresultoftheconflict.Atthecomponentlevel,therefore,designengineersmustunderstandthethermalexpansionandthermalstresscharacteristicsofthematerialsmakingupthepartstheyuse.Atthesystemlevel,designengineerspaysomeattentiontostructuralconsider-
ations,butinthermalmanagement,theseconcernstendtotakeabackseattothepredictionofthelikelyflowpath.Bydirectingastreamofairpastheatgeneratingcomponentsorsensitivecomponents,convectioncanbeusedtodirectlyremovethermalenergyfromtheenclosure.Maintainingathermalenvironmentthatallowsthecomponentstoremaininasafetemperatureoperatingrangeisthedominantfocus.The analysis at this level usually does not consider all possible conditions.
Instead, attention is focused on worst-case scenarios. “We don’t look at allpossiblescenarios,”saidGarySchwartz,EngineeringFellowatRaytheonNetworkCentricSystems.“Wejustlookattheworstscenario.Iftheelectronicscansurvivethat,theycansurvivemundaneconditions.”Unfortunately, thedifficulties encountered in electronics designare ramping
upassystems,interactions,andoperatingfactorsbecomeincreasinglycomplex.“Previously, we would have looked at individual parts, by themselves,” saysSchwartz.“Individually, thepartsmaybeall right,butthe interactionofall thepartsmaynot.Thekeynowistolookathowallthepartsworktogether.”Thissituationisexacerbatedbythefactthatmodernelectronicsystemsneedto
bedesignedtostrictenergyusageguidelines.Thismeansthatengineerscanalsonolongerrelyonthe“brute-force”approachoffloodinganelectronicspackagewiththelargestpossibleamountofcoldair.Again,whereamoresubtleapproachisrequired,theinsightgainedthroughsimulationiskeyindetermininganenergyefficient,yeteffectivecoolingsystem.g
The control of component and system temperatures remains one the most signif icant chal lenges in the design of electronic systems. From chip to chassis and beyond, excessive thermal loading l imits the maximum performance of an electronic device and signif icantly increases the energy footprint of the system.
One solution to these problems is the STAR-CCM+ surface wrapper: a tool that creates a geometric representation by shrink-wrapping a high-resolution surface on the complex aspects of the geometry. It allows the user to ignore many of the inadequacies of the 3D model and create a geometric representation that is ready for simulation.
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challenges Thetraditionalphysicsinvolvedinthesimulationofelectronicsystems,suchasheatconductionandconvection,arewellunderstood.Onpaper,manysimulationtoolshavetheabilitytosolveproblemsinvolvingthesephysics.However,solvingindustrial strength problems, within the constraints of a product developmentprogram,isoftenmuchtougherinrealitythanitseemsonpaper.Today,manytraditionalsimulationtoolsstruggletokeepupwiththefast-paced
developmentschedulesthatengineeringteamsareconfrontedwith.Inaworldwhere customers need to know performance characteristics in order to keepdevelopmentmoving forward, simulationhas some inherent inefficiencies thatarekeepingdesignteamsfromdeliveringtheirresultsquicklyenoughtohavethemaximumimpactonaprogram.Theinefficienciesareintwomainareas:thesimulationprocessitselfandthe
limitednumberofphysicalenvironmentsthatcanberepresentedvirtually.Oneofthebiggeststumblingblocksisgeometrycreationandgeometrycapture.
the Starting Point Geometryisthestartingpointofanysimulation.Itisthevirtualrepresentationofasystemanditscomponents.ThegeometrytypicallycomesfromCADtools,ineithera2Dor3Dformat.CADgeometrymaycomeinasimplified,conceptualform,quicklycreatedwithoutadequateattentiontoerrorsor,morelikely,isoverlydetailed,containingmoredefinitionthanthesimulationrequires.Bothproductiongeometryandsimplifiedgeometrycancontainalotoferrors
andproblemsthatmustbeaddressedbeforethegeometrycanefficientlybeusedasabasisforanengineeringsimulation.Usually,adesignengineercreatesthegeometry.Therearetimes,however,wherenoCADdataexists,whichforcesthe
simulationengineertocreateitdirectlywithinthesimulationtool.“Themostdifficultpartof theprocess isdealingwithgeometricallycomplex
parts—taking those parts from a designmodel, such as Pro/Engineer or NX,andputtingthemintosomekindofsimulationcodesothatyoucanusethatgeometry,”saidRaytheon’sSchwartz.“Thereispotentiallyalotofclean-upthathastobedone.Sometimesyouhavetomassagethegeometryofthepartstocreateamodel.”Using the wrong simulation tool, engineers are forced to spend weeks
attemptingtomakethegeometrysimulation-ready.Theyhavetode-feature it,remodelorcompletelyremoveaspects,destroyingintheprocessthelinktotheoriginalCADmodel.Thisreducestheimpactthatsimulationcanhaveonproductdevelopmentbecausethetimerequiredtocreatethegeometryandprepareitforsimulationissometimeslongerthatitwouldtakeanengineertoprototypeandtestaconfiguration.“Thereare timeswhen itmay takehoursordays just toworkononepart
togetittothepointwhereyoucanactuallyincludeitinyoursimulation,”saidSchwartz.“Thatisthebottleneck.Timeisarealfactor.Youdon’twanttospendthree months building a model because by that point it’s of no relevance.Youneedtodothingsfairlyrapidlytohaveanimpactonthedesign.” the Fix One solution to these problems is the STAR-CCM+ surface wrapper: a toolthat creates a geometric representation by shrink-wrapping a high-resolutionsurface on the complex aspects of the geometry. It allows the user to ignoremanyof the inadequaciesof the3Dmodelandcreateageometric represen-tationthatisreadyforsimulation.
www.cd-adapco.com/downloads/special_reportsVisitthelinkbelowforourELECTRONICSSPECIALREPORT:
ABoVEFlowstreamlinesandtemperatureprofileunderextremeconditionsinsideapowersupply
..::FeATURe ARTICle Electronics
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For those involved inelectronicsdesign, themostcommonuseof thesurfacewrapper is for the enclosures that house large numbers of components. Thesurfacewrappercreatesonesolidsurfaceover theseareas. If theenclosure ismadeofsheetmetal,thesurfacewrappercanquicklyhelptheuseraddressthegapsinherentduetobendreliefs,assemblytolerances,andoverlappingtabs.Iftheenclosureismadeofmoldedparts,thecomplexgeometryofthepartsthemselvesaswellastheinterlockingconnectionbetweenpartscanbequicklypreppedforanalysisbythesurfacewrapper.Thecornersofenclosuresoftenhavegapsthatpresentsignificantproblems.
“ThedesignermayhavebuiltarackinCATIAthatshowsgapsaroundtheshelvesformanufacturing tolerance,” saidGulfstream’sSlater. “The gapsbecomeflowpathsthatinrealityshouldnotbethere,andtheywon’tclosetheboundaryproperlyfromamodelingperspective.”Oneofthesurfacewrapper’ssettings,calledgapclosure,letsyouspecifythe
sizeof theholes intheassemblythatareclosedautomatically.Anothersettingcalled contact prevention, allows the simulation engineer to maintain spacingbetweencomponentsthatshouldnotcomeincontactwitheachother.Withthesurfacewrapper,youcancontrolthereplica’sresolutioneitherglobally
oronthepart,surface,andedgelevelandautomaticallytakecareofproblematicareas.Thesurfacewrappernotonlyprovidesawayoftransformingbadordifficultgeometry intoaformreadyforefficientsimulation; italsohelpstodramaticallyshortenwhathasbeenacumbersomeandtime-consumingprocessthatpreventeddesignersfrombeingmoreproductiveandreapingthefullbenefitsofsimulation.“Thespeedofbeingabletoputthesemodelstogetherandstartusingthemis
quiteimportant,”saidSlater.“Thepowerwithwhichwecanhandlethegeometriesandmeshingwithinthesimulationcodeisquiteimportant.”Onceahighqualityclosedsurfaceisavailable,STAR-CCM+canautomatically
filltheenclosurewithacomputationalmeshoftrimmedhexahedralorpolyhedralcells,allowingthesimulationtoproceed.
new Problems, Broader Horizons Untilrecently,electronicsdesignershavebeenfullyoccupiedwiththesolutionoftraditionalproblems,suchasconductionandconvection.However,advancesinsimulationtechnology(suchasthosedescribedabove)arefreeingdesignerstotacklemoreunusualproblemssuchascontaminationresistance,waterintrusion,andcondensation.Forexample,militaryelectronicsystemsneed tobeable tooperate inthedesert,wheresandingressionisachallenge.Portableelectronicdevicessuchascellphonesareincreasinglyrequiredtowithstandwaterintrusion.Even cooling problems are now increasingly relying upon “non-standard
technology”.Tomeettheincreasedcoolingrequirementsofthelatestgenerationofelectronicequipment,engineersareexpandingfromsimpleairandgascooling
systemstoliquidandspraycoolingapproaches.Todevelopthesenewsystems,theymustuseheatexchangermodelsthatallowthemtointeractwithmultiplefluidsandspraycooling,aswellasrepresentmultiphaseenvironmentswhereliquiddropletsinteractwithair,andevaporationandcondensationcomeintoplay.Theproblemisthatmanymainstreamsimulationtoolscapableofsolvingsimple
conduction and convection problems cannot accurately represent the physicsrequiredtosimulatethesescenariosvirtually.Asafull-spectrumsimulationtoolthatisusedtosolvefluidandstructuralmechanicsproblemsoverawiderangeofindustries,STAR-CCM+isuniquelyabletoaddressthemostdifficultphysicsproblemsthatelectronicsengineersencounter.Thisgivesthemtheconfidencetodevelopandoptimizecoolingtechnologiesforthisnewclassofelectronicsproblems,limitedonlybywhatisphysicallypossible,andnotbyshortcomingsoftheirsimulationtool. Benefits of Best-in-class Simulation Whenyoulookatthebottomlineofthebalancesheet,thequestionisn’twhetheryoushouldusesimulationtodesignelectronicsystems.Simulationenablesyouto visualizewhat ishappening in thecomponentor systemyouaredesigningand why. It allows you to make informed design decisions, optimize productperformance,managerisks,andpursueinnovation.“Onceyoustarttousesimulationandyoubuildyourconfidencewithit,youcan
pushtheboundariesofyourdesignandmakesurethatyouachievethemaximumvalueoftheproduct,”saidGulfstream’sSlater.“Afterweseethesimulationresults,thelightbulbgoeson,”saidRaytheon’s
Schwartz.“Untilwedothesimulation,it’sdifficulttoknowwhat’sreallygoingtobethebehaviororresponse.Wearejustguessingunlesswedosomekindofsimulationbecausethingshavegottensocomplexthatyoureallydon’tknowwhatthebehaviorisgoingtobelikeuntilyoubuildthemodel,runthesimulation,andlookattheresults.Itshowsuswhatwehavetochangetogetwhatwewant.”The realquestion iswhat featuresyoushould require in thesimulation tool
thatyouuse.Findthetoolthatincludesthemostefficientsurfacewrapper,andtheprocessofconvertingCADdataintoasimulation-readygeometryisnolongerprohibitive in termsof timeand resources.Complex surfacesdonotprecludeaccuraterepresentation.Selectthesoftwarethatoffersadvancedmeshing,andnoprojectistoobig.
With the right mesh, you can get the optimum benefit from your computingresources.Choose thesimulation tool thathas thegreatest varietyofphysicsmodels,
andyoucandesignthenewclassofelectronicsthathavecapturedthemarket’sattention.Alsomakesurethatyouchoosethesimulationtoolthatprovidesthebestsupportorganizationtoallowyoutomosteffectivelyleveragethesoftwareinthedesigncycle.<
ABoVESimulationresultsshowingflowthroughacoolingfanandtemperatureprofileonaheatsinkinsideanelectronicsenclosure
i ORDERORDOWNLOADOURELECTRONICSSPECIALREPORT: www.cd-adapco.com/industries/electronics
For electronic devices, temperature is a l imit ing factor. Packing technology, driven by constant consumer demand and competi t ive pressure, al lows higher power density than current cool ing technology can handle. Sustained elevated temperatures act to not only reduce component eff iciency, but also to reduce product l i fe. Effect ively control l ing the temperature of electronic systems, in an intel l igent and sustainable manner, is therefore the key to producing smaller, more powerful and more resi l ient electronic devices.
stephen Ferguson - CD-adapco
BELoW Trimmedmeshandpressuredistribution
Is your electronics Cooling software
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www.cd-adapco.com/industries/electronicsReadabouthowoursoftwareisusedintheElectronicsindustry:
Did You Know?You could fit more than 700 million transistors on the head of a pin!
Air-cooling, while effective for low- to medium-power applications (where space and noise are not a concern), is generally neither practical nor cost-effective for high-powered systems. put simply, the “brute force” approach, in which high-temperature components are strapped onto a large aluminum heat sink and blasted with cold air is no longer an option. So, what is the best method for cooling high-power electronics when air solutions are not practical or possible?
The future of electronics cooling involves the implementation of cooling strategies that leverage multiple modes of heat transfer. The problem for engineers developing electronics cooling solutions is that many of the simulation tools were developed entirely for analyzing simple “bread-and-butter” scenarios. These tools, although adequate for obtaining a “quick and dirty” fan-assisted air-cooled solutions, are generally not fit for simulating the more advanced physics required to represent more recent and sophisticated cooling strategies.
In this article, we look at some of the problems that simulation software will have to face in the electronics industry, and ask the question: “Is your electronics cooling software fit for purpose?” A Question of scale The length scales represented in electronics cooling problems can span 11 orders of magnitude: from individual transistors that are measured in nanometers (of order 10-9 m) to entire datacenters (of order 102 m).
Now obviously, no tool can account for every single electronic component in a datacenter cooling simulation. Even if it were possible to do so, it is doubtful that such a simulation would provide additional useful information. Out of necessity, engineers use a combination of simplifying assumptions and imposed boundary conditions to focus the simulation on those length scales that are most important for the simulation (using generous amounts of “engineering judgment” in the process). However, care must be taken not to over simplify things: if the assumptions are too great, or the imposed boundary conditions are too unrepresentative, then the results predicted by the simulation begin to diverge from those that would occur in reality. When this happens, no amount of judgment (engineering or otherwise) can rescue useful data from the simulation. Worse still, wrong or inaccurate results can mislead the design process, potentially sending the product up a non-optimal design branch.
So, ideally your simulation tool will allow you to solve problems across multiple length scales. Instead of just simulating flow across a single circuit board, you want to be able to model a whole blade server, or better still, how several blade servers interact with each other and their environment.
Natural Convection and Thermal Radiation In traditional forced convection “air-cooled” systems, thermal radiation plays a relatively minor role in the overall heat transfer, typically accounting for less than 5% of the thermal energy rejected by the system (with the rest split evenly between convection and conduction).
However, in “no flow” situations, whether by design or in unintentionally “dead” regions of the compartment, radiation plays a much more important role accounting for between 30-50% of heat transfer.
Simply neglected in many simulations, for the reasons described below, including radiation heat transfer in a simulation will generally act to decrease maximum temperature in the system, spread out the temperature distribution and reduce the exterior surface temperature (touch temperature). g
❐ FACT
sTar-CCm+
STAR-CCM+ is designed to handle complex problems and large model sizes. It has been
used by our industrial partners for calculations numbering billions of computational cells far
beyond the size of any electronics-cooling problem. No matter how big, or how complex your
design scenario is, STAR-CCM+ allows you to solve it without compromise, using a model
size that fits your problem and ultimately utilizes less assumption.
Below - Team Lotus Renault CFD Center: a $50M underground bunker for computers
multi-Core processingsTAR-CCm+ includes parallel view factor calculation, which allows users to exploit the processing power of multiple computer cores when performing radiation view factor calculations.
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More than just a CFD code, STAR-CCM+ is a complete multi-physics toolbox, able to solve flow, thermal and stress problems involving multiple phases. From liquid jets to water ingression, STAR-CCM+ allows you to simulate any cooling strategy that you can define, and even the effect of what happens when those strategies go wrong.
The All-in-one muti-physics Toolbox
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Fit for purpose?
my electronics Cooling software:Can handle complex geometries without gross simplification
solves problems that span multiple length scales
solves problems that involve natural convection and radiationAllows me to simulate problems involving liquids as well as gasses
However, including radiation heat transfer can significantly increase the computational overhead for a simulation, as view factors (basically lines of sight) must be calculated for every computational face of every component in the system. Although these view factors need only be calculated once per geometry, this process can be computationally expensive even for a large uncluttered enclosure. In a typical crowded electronics enclosure, consisting of hundreds, if not thousands of components, calculating these view factors is beyond the capability of a single processor machine (both in terms of memory requirement and physical time needed to complete the calculation).
By including radiation, you can reveal the effects of an additional heat flow path – this is critical in low flow or no flow situations and can be important when trying to squeeze every degree of cooling from a forced convection system. liquid Cooling: Chilling, Dunking and spraying While air-cooling continues to be the most widely employed method of thermal management, its ultimate effectiveness is always limited by the fact that air has relatively poor thermal capacity compared to other fluids. For serious cooling impact for high-power density systems, designers are increasingly turning to different types of liquid cooling.
A common feature of liquid-based cooling systems is that they exploit the additional heat transfer of phase change to increase the cooling effect of the liquid. Because of the higher thermal capacity of the coolant liquid, they benefit from greater sensible heat transfer (which raises the temperature of the coolant) and latent heat transfer (which changes the phase of the coolant, through boiling or evaporation).
The simplest way of doing this is by “indirect” liquid cooling, where the coolant never comes into direct contact with the electronic component being cooled, usually accomplished through the attachment of a liquid cooled “cold plate” which is attached to the chip.
A more effective (although less practical) solution is to submerge the chip directly into a (non electrically conductive) coolant. If the temperature of the component increases beyond a critical level (the boiling point of the liquid), then nucleate boiling will commence, greatly increasing the heat flux from the chip to the fluid. At high temperature, this approach is around 5 times more effective than indirect liquid cooling, and about 25 times more effective than direct air-cooling. However, this approach makes routine maintenance much more difficult (as the components must be removed from the liquid bath and cleaned prior to inspection). Care must be taken so that the boiling regime does not progress to “film boiling” at which point the component becomes surrounded by a film of vapor, and heat transfer is suddenly reduced, resulting in a sudden rise in component temperature, followed by rapid failure.
Most effective of all are direct spray systems, in which a fine mist of non-corrosive, non-conductive coolant is sprayed directly on the surface of the component, forming a liquid film that rapidly evaporates. The coolant vapor is extracted from the enclosure and condensed, rejecting heat to the surroundings.
The problem? As we discussed above, many simulation tools are specifically designed to handle single-phase air-cooling and, at a push, simplified indirect liquid cooling (modeled using a source term or a boundary condition). If you want to explore any of the more advanced liquid cooling technologies, your simulation tool needs to be able to model multi-phase calculations, which include the interaction between air, liquid and various gasses, as well as boiling and phase change. Without this functionality, your simulations and your designs will be limited to simple, ineffective air-cooling. other Advanced physics Of course, it’s not all about cooling. Engineers in the electronics industry have a whole multitude of problems to deal with, to name but a few: • fan performance and acoustics (if you’ve ever been inside a datacenter, then you’ll know how important that is); • water intrusion; • dust build ingress and accumulation; • hydrogen build up (from battery decay).
The benefit of employing a fully featured simulation tool is that, no matter how rarely these problems occur, your engineering software will allow you to solve them when they do. <
i FOR MORe inFORMATiOn ABOUT CD-adapco PRODUCTS: www.cd-adapco.com/products
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InDesA came to the conclusion that there is a demand for a highly optimized virtual test environment that is fast, flexible and cost efficient in comparison with traditional physical testing.
InDesA is an engineering consultancy and services company with specialization on complex fluid flow and heat transfer simulation and analysis for industrial applications. Although the history of InDesA is still young, our leading engineers look back at 20 years of experience in the field of automotive and power train development. Besides we have developed simulation techniques for other competence fields like general aerospace, marine, energy and for the environmental sector.
InDesA Virtual Test Facility CenterDr. Gerald Seider - InDesA
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The demands of modern vehicle design require that many components be designed and tested simultaneously. Almost al l of these components need to be specif ical ly opt imized for their role in the part icular vehicle design, and many ut i l ize innovative technology. With l i t t le t ime for construct ion and test ing of physical prototypes, along with the need for fast adaption of components due to changing module and system requirements, there is a compell ing case for the introduction of more virtual test ing at component level in vehicle development programs.
The need for simulation in the “V-Model” Development Process The development of any vehicle takes several years, incorporating many thousands of hours of design and testing. To manage this process, most manufacturers of vehicles such as cars, buses and trucks have adopted the so-called “V-Model” development process.
The V-model process starts with the design of the overall vehicle system. Once the system has been fully specified, the vehicle is divided into a series of modules. Each of these modules is essentially considered as a separate sub-system for design purposes (although in practice the many interactions between different modules must be accounted for). The final and most detailed part of the design stage involves the design of the individual components that make up the modules such as heat exchangers, pumps and turbochargers. Having reached the bottom of the “V”, the verification branch becomes active and the individual stages are subjected to testing, starting with component level verification, then advancing to the module and finally to the vehicle level verification.
One of the most critical stages occurs as the process approaches the bottom of the “V”. Here, the vehicle components need to be designed and verified almost at the same time. While in the past it was often possible to select tried and tested “off-the-shelf” components, the complexity of modern vehicles requires that almost every component should be specifically designed and optimized for the overall system. Put simply, this means there is no time to build physical prototypes and measure performance on test rigs. The only practical solution to this problem is the adoption of a “virtual test rig” in which numerical simulation of virtual prototypes takes the place of physical testing and validation.
This becomes even more critical when dealing with innovative components that affect several parts of the system, such as the
combined alternator/water pump unit described below. Such a unit influences both the cooling and electrical systems of the vehicle, creating an interdependence between them. Therefore, the system designer requires detailed operating characteristics of both the alternator and the water pump, while on the other hand it is very difficult for the unit supplier to build a prototype if the system designer has not completely defined his requirements. This creates an “iterative loop” that must be quickly resolved. Here again, we think that a virtual test rig would be helpful and beneficial for the development of innovative components.
The InDesA Virtual Test Rig InDesA came to the conclusion that there is a demand for a highly optimized virtual test environment that is fast, flexible and cost efficient in comparison with traditional physical testing. Such a virtual test center would be useful for performance prediction of standard automotive accessory units, producing performance maps for fans, pumps, compressors and heat exchangers. The Virtual Test Center would also be beneficial for functional testing & confirmation of larger engine and vehicle thermal systems such as coolant circuits, heat exchanger packs in the front-end of a vehicle, electronics cooling, and the cooling of battery packs.
The figure above shows our main applications for accessory units such as cooling fans, compressors, coolant pumps and heat exchangers. For these, performance maps, e.g. pressure over volume flow rates for different fan or impeller speeds, are usually produced. Heat exchangers are slightly more complex as they feature two different fluids as well as heat transfer through the structure. For these, heat transfer and pressure loss maps are typically produced.
The figure below shows more complex units, such as the water g
ABOVE Flow through a complete coolant circuit
TOP Combined generator/coolant pump from IGEL AGABOVE Flow through the combined generator / coolant pump
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pumpandheatexchangerbeingintegratedwiththecoolantsystem,ordifferentheatexchangersandafanbeinggroupedtogetherintoafront-endcoolingpack.Thosesetupsareusedforfunctionaltestingandvalidation.Twomoreapplications,whicharesimilartoheatexchangersbutwithamorecomplicatedheatfluxpath,dealwithbatteryandelectronicscooling.
Alloftheseapplicationsareobviouslyverycomputationallyintensive:inordertoproduceperformancemaps,manyoperatingpointsneedtobecalculatedinparallel. InDesAhas therefore invested in a computer clusterwith112nodes,whichusesahighspeedcommunicationswitch.Thishardwareallowsustoeasilyoutperformconventionaltestrigswithrespecttooperatingtime.
AttheheartofthevirtuallabisSTAR-CCM+,acomprehensiveengineeringphysicssimulationtoolthatprovidesanengineeringprocessforsolvingproblemsinvolvingfluidflow,heattransferandsolidstress.STAR-CCM+ishighlyautomated,whichmeansthatparametricdesignstudiescanbecompletedwith littleornomanualinput.
Anadditionalmodule,theFacilitySupply,isrepresentedby1Dsystemmodelsfortheengine,coolantorlubricationsystem,andaimstoenhancethecomponentsintegratedenvironmentbyincludingthewholesystem.Theunderlyingmotiveistoeventuallybeabletoreproducethesystemcharacteristicsofthecoolantcircuit,sothenumberofoperatingpointsneededtogenerateaperformancemapcanbenarroweddowntowherethepumpactuallyoperates.
eGR Cooling module Design Inthisfirstexample,wearelookingatatypicalEGR(ExhaustGasRecirculation–atechniqueusedtoreducenitrogenoxideemissions)coolingmodule.Thereisoneinletandoneoutlet,fortheexhaustgasandthecoolanteach,wheremassflowratesandtemperaturesareprescribed.Also,theenvironmentisdefinedintermsoftemperatureandheattransfercoefficients.WithaGT-SUITEenginemodel,thecharacteristicflowratesandtemperatures,orthepressuredifferencebetweentheexhaustinletandoutletastheEGRcoolerconnectstheexhaustwiththeintakemanifold,canberetrieved.WithaGT-POWERmodel,thehighlyfluctuatinggasflowcanalsobecaptured,whichisessentialintheheattransferanalysis.
AfewadditionalboundaryconditionsareneededforthepositionsofthebypassflapandtheEGRvalveintegratedinthecoolingmodule.ThemodelsetupcanbedonemostefficientlyinSTAR-CCM+wheredirectthermalfluidstructurecoupling(whichincludesallthedetailsofthepipesorplateswithfinsordimples,aswellasdetailsofflapsandhingestoaccountforflowleakage)canbeused.
Thesimulationresultswereasfollows:theoutlettemperatureandpressurelossofthecoolantcouldbepredicted,aswellastheareaswhereboilingislikelytooccur.Wecouldalsopredictthevolumeflowratesforthevalveseatcoolingandassesstheflowuniformity.Fortheexhaustgas,themostimportantresultwasthepredictionoftheoutlettemperatureandthepressureloss.Wealsopredictedtheforcesonthebypassflap,assometimesflowleakageisthereasonwhytargets
arenotfullymet.Structuraltemperatureswerecomputedeverywhere(andmostimportantlyinthevalveseatarea),whichenabledastructuralstress/strainanalysistobeconductedtogainsomeinsightintofatigueproblems.Finally,theheatfluxwascomputedfromtheexhaustthroughthestructuretothecoolant.
Byrunningenoughoperatingpointsfortheheatexchanger,wecouldcalculatethe Nusselt correlation for heat transfer and thus derive a full heat transfermap.Suchcorrelationsareusuallyneededfor1Dsystemanalyses.However,itshouldbestressedthatavirtualtestrighasmorecapabilitiesthanjustproducingperformancemaps.Theanalysisoftheresultscanhighlightanyweakpointsinthedesignandfacilitateimmediateremedialredesign.
Innovative pump Design Oursecondexampledealswithacombinedgenerator/coolantpumpdesignedbyoneofourpartnercompanies,IGELAG.Thisdesignhasrecentlywonthe“awardofinnovation”grantedbytheWürzburgerAutomobilGipfel2010.Itconsistsofabeltdrivengenerator,aclutch,andanelectricmotorwithacoolantpumpattheend.Thegeneratoriswatercooledwiththehelpofawaterjacket.Thewaterpumpcanbedrivendirectlybythegeneratorshaftiftheclutchisclosed,inwhichcasetheelectricmotorisdisengaged.Iftheclutchisopen,thee-motorcandrivetheimpellerindependently,eveniftheengineisswitchedoff.So,inthefirstcase,wehaveamechanicalwaterpump,andinthesecond,anelectricwaterpump.Thisisparticularlyusefulforturbochargercooling,whichmustcontinueaftertheenginehasbeenswitchedoff.
Forthedesignofthisinnovativepump,wehadspecificfluidmechanicaldesigngoals.Wehadtargetsforgeneratorcooling,pumpperformance,andefficiency.Wehadtokeepthepressurelossofthewaterjacketlowtoavoiddegradingthepumpefficiency.Toachievetheperformancetarget,wehadtodesignanewhighspeedimpellerasthegearofthebelttransmissionforgeneratorsismuchhigherthanforconventionalwaterpumps.Forthisparticularcase,wetookovernotonlythetaskofpredictingthepumpperformance,butalsothedesignoftheimpeller,thevolute,andthegeneratorcoolantjacket.Thisisaclearexampleofhowthevirtualtestrigapproachenablesthedirectinteractionofdesignandverification.
Thechallengewithmarketingsuchaconceptisthat,asyouapproachdifferentOEMs,eachspecifiesa listofdifferentwishes, requirements,and targets.Thismeansthatthegenerator/pumpunitmustberepeatedlyadaptedandredesignedinaveryshorttime,beforefinallyprovingtotheOEMthatthecomponentmeetsthe required specifications. Cost efficiently, this can only be achievedwithin avirtualprocesswheredesignandverificationinteractdirectly.
Withjustasinglefluidstream,themodelisnottoocomplicated,usingasingleinletandasingleoutlet.Forthispurpose,themovementoftheimpellerdoesnotneedtobemodeledexplicitlyanditissufficienttousethecomputationallylessexpensivemethodofMultipleReference Frames (MRF). The simulation resultspredictedthevolumeflowrateandthepressurerisefordifferentpumpspeeds,
ABoVE Morecomplexarrangements,wheremultiplecomponentsarecombined,requiremorecomputerintensivetreatment.
ABoVE Fans,compressors,coolantpumpsandheatexchangersarecharacterizedbymakingaperformancemap.
www.cd-adapco.com/industries/automotiveVISITTHELINKBELOWFORMOREAUTOMOTIVESTORIES:
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i FORMOREINFORMATIONABOUTInDesA,PLEASEVISIT: www.indesa.de/
EGRCoolingModuleDesign EGRStructuralTemperaturesEGRCoolantflow EGRExhaustGasFlow
aswellasthehydraulicefficiencybydeterminingthetorqueduetopressureandfriction.We also predicted the onset of cavitation. For thewater jacket of thegenerator,wecalculatedthepressurelossandheattransfercoefficienttoassessthecoolingcapabilities.Finally,weextractedthepumpperformancemap;affinitylawswerehelpfulincompletingthismap.IfaGT-SUITEmodelwasaddedtothecoolantsystem,wecouldderivetheoperatingconditionsunderwhichthepumpisbalancedandestablishwherethepumpwouldbestoperate.Accordingly,wecouldcutdownthenumberofoperatingpoints,therebysavingasignificantamountofcomputationaleffortandtime.
more Complex systems Havinginvestigatedsingleaccessoryunits,itcanbecomeinformativetolinkthemtogether.Inthiscase,wecombinedacoolingfanwithdifferentheatexchangerstoformasimplifiedunderhoodmodelfortheinvestigationofawholecoolingmodule.For the fan,wecaneitherusea3DCFDmodelorderiveaperformancemapandsimplifythefanintheunderhoodmodelasadiscwithamomentumsource.Aswiththeheatexchangers,wedonotneedtoresolvetheentiregeometrybutcanusetheNucorrelationderivedbyvirtualtestingorbyconventionalhardwaretesting.
Wecameupwithausefultestrigset-uptoinvestigatethemassflowandheattransferratesofthecoolingmoduleofacarwhosefront-endgeometryisnotyetknownordecided.ByusingadetailedCFDmodelforthefan,wecouldalsoaccountfortheflowinteractionbetweenthefanandtheengineandasseshowitdowngradesthefanperformance.Needlesstosay,wecouldeasilyshiftthepositionsoftheheatexchangersandtheenginetoadaptthemodeltochangesintheenginecompartment. Coolant Circuit Design Anotherexampleofausefulcombinationofaccessoryunitsisthecoolantcircuit,whose3DCFDmodelisprincipallymadeoftheCFDmodelsofawaterpumpandheatexchangers(coolantsideonly).Tocompletethemodel,thegeometriesoftheenginewaterjacket,thermostat,connectingpipes,andhosesareneeded.
A3DCFDmodelofacompletewaterjacketcanbeusedtoinvestigatetheflowratesintheentirecoolantsystemfordifferentpumpspeedsandthermostat/valvesettings.Ifthemodelissufficientlydetailed,itisalsopossibletoinvestigatethefillingprocedureandde-gasbehavior.
Conclusion TheInDesAVirtualTestFacilityCenterisanefficientandenvironmentallyfriendlyconcept.
Itisefficientbecausewebuiltastandardizedprocedureforadefinedsetofapplications.Thevirtualworldallowsustoeasilycustomizethoseprocedurestothespecificneedsandwishesofourcustomers.Thisismadepossiblebyourcomputa-tional test facilitycenter,which ispoweredbyover100processors, linkedwithahighperformancecommunicationandstoragesystem,andtunedforoptimalperformanceofSTAR-CCM+.
Itisenvironmentallyfriendlybecausetheclusteriscooledusingonlystandardventilation and no air conditioning. Considering that a single car radiator candischarge 100 to 150 kW into the environment, it is obvious that numericalsimulationisfarmoreenergyefficientthanthephysicaltestingofprototypes.<
ABoVE The“V-Model”developmentprocess
SYStEM
ModuLE
coMPonEnt
VEHIcLEdESIGn
VErI
FIcA
tIon
❐ FACT
design proCess
The InDesA Virtual Test Facility Center is based around the principles of High Fidelity,
Repeatability, and Comparability
High FidelitybecauseweusehighresolutionCFDmodelstoensurethefulldetailofthe
geometry is captured (accounting for even the flow leakage in pumps, hinges, etc.). By
exploiting the strength of theSTAR-CCM+physicalmodel library,we are able to include
radiation,two-phaseforboiling,and,ifneeded,akinematicmoduleforpressureactuated
flaps.
Repeatability because theCFDmodel of a test rig and the test object are packed and
archivedwith all the results for reuse. Additional operating points can be run at request
anytimeinthefuture.
Comparabilitybecausewewant tobeable tocompare resultsatdifferentstagesof the
prototype,usingthesameboundaryconditions,solutionmethod,andmeshresolution.
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sunroof buffeting & Acoustical Impedance of Flexible structuresFred mendonça & Deborah eppel - CD-adapco
BELoW3DRoofPanelRepresentation
❐ FACT
did yoU KnoW?
WHAT Is THe DIFFeReNCe beTWeeN A mooNRooF AND A sUNRooF?
Do you think that a moonroof is a sunroof operated by night or while listening
to Michael Jackson’s music? Then this box out is for you! According to www.
sunroofs.org, “Sunroof is the generic term used to describe an operable panel
in a vehicle roof which can let in light and/or air”. It includes pop-up, spoiler,
folding, topslider, panoramic, inbuilt, and removable panels. “Moonroof is a
term created by Ford in the 70’s, yet is now used generically to describe glass
panel inbuilt electric sunroofs.” In other words, a moonroof is just a type of
sunroof. Almost disappointing…
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Imagine sitting in your car on a sunny summer day, driving through
the beautiful countryside and listening to your favorite program on
the radio. everything is perfect, you even have a full tank. The air
outside is fresh and pure, and you decide to open the sunroof to make the
most of this idyllic, if slightly clichéd, situation. As you do so, the sound of
the radio gets drowned by the buffeting of the sunroof. You are now facing
a difficult choice: listening to your favorite radio program without damaging
your hearing, or breathing some fresh air? sound familiar? You’re not the only
one.
Numerous car components produce a perceivable aeroacoustic signature.
For example:
External components such as side mirrors, A-pillars and windshield wipers:
thesedirectlyexcitethevehicle’sglasspanels,whichtransmitnoisetothedriver’sear;Under-the-hood turbo-machines such as the cooling fan and turbocharger: theirnoisecanbeheardabovetheidlingengine;Ducting and climate control system components such as the blower fan and
flaps:thesecreatenoisethatisdirectedintothepassengercompartment;Open apertures such as sunroofs and windows:thesesufferbuffetingcausedbyoscillationoftheseparatedshearlayerattheapertureleadingedge.
Automobilemanufacturers and component suppliers are keen to demonstrateexpertiseinappliedtechnologiesfornoiseminimization.However,althoughCFD
aeroacousticsmethodologiesarewellestablished,simulationhasnotyetbeenconsistentlyadoptedinproduction,designanddevelopment.Therefore,toproveCFD’sviabilityandreliabilityintheaeroacousticsfield,thereisaneedtoprovidewellvalidated,fastandrepeatablemethodologiesacrossallthesesectors.CD-adapco is pioneering aero-vibroacoustics methodologies, working with
establishedexpertsandCFD-complementarysoftware.WhileSTAR-CCM+hasdemonstrateddirectcouplingtoindustry-leadingacousticandvibroacoustictools,oneclassofaero-vibroacousticsimulationisviableentirelywithintheSTAR-CCM+environment.We illustrateherea fully integratedflow-structures interactionasappliedtosunroofbuffeting.
simulating sunroof buffeting
Thenoiseassociatedwithsunroof(orside-window)buffetingiscausedbyunsteadyflowoverthesunroofopeninginteractingwiththeroofpanelandradiatingsoundtothevehicleoccupants.Onewaytoreducethenoisesignatureassociatedwiththisphenomenonistoadddeflectorstochangetheflowpatternovertheopening,oftenbyintroducingadditionalmechanicalparts.Anotherwayistoaddflexibilitytothesunroofpanelbychangingthematerialitismadeof.Inarecentexperimentalstudy[1,2]performedbytheAeroacousticsConsortium
ofGermanAutomotiveManufacturers,aseriesofexperimentswereconductedontheSAEBody,modifiedtoincludeasunroofandpassengercavityvolume.Theresultsestablishedthattheaeroacousticsbuffetingnoisesignatureatthedriver’searlocationissignificantlyaffectedbymaterialdampingpropertiesofthepanelsusedinthemodel.g
With the transport industry facing a continuing demand from customers and regulators to improve the aeroacoustic and vibroacoustics performance of their products, reducing f low-induced noise has become more relevant than ever. Tradit ional Fluid-Structure Interact ion (FSI) CFD coupled methods have been judged too t ime consuming, technical ly chal lenging and/or computat ional ly expensive to lend themselves to production level aeroacoustics analyses.
However, by developing and commercial iz ing a new f luid-structure integrated capabil i ty for aeroacoustics simulat ions with structural impedance effects, CD-adapco has shown that i t is no longer the case. . .
The noise associated with sunroof (or side-window) buffeting is caused by unsteady flow over the sunroof opening interacting with the roof panel and radiating sound to the vehicle occupants.
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Validation tests using CD-adapco’s flagship software, STAR-CCM+, wereconducted, initially assuming themodel structure tobeperfectly rigid.Resultsprovedtobeexcellentthroughmostofthevehicleoperatingspeedrange,withtheexceptionofaminorover-predictionoftheoverallsoundpressurelevel(OASPL)overacriticalspeedrange,wherethematerialdampingeffectswereobservedtobemostpronounced.Thisover-predictionwasputdowntotheinitialrigidityassumptionandwasthereforenotconsideredtobeamajorconcern. simulation with Impedance effects
CD-adapcodecidedtore-runthesimulationswhiletakingintoaccountthematerialstructural impedanceeffects.UsingSTAR-CCM+,aseriesoffullycompressibleDES calculationswere performed at a nominal vehicle speed of 80 kph. Thiscombination, importantly for this application, takes into account the flow andacousticalfeedbackwhichisastrongmechanismatthisspeed.Approximately3millioncellswereusedtorepresentthehalf-body,includingabout500,000cellstomodelthesolid.STAR-CCM+ is unique in its ability to perform two-way coupled fluid-solid
interaction: itusesaFiniteVolumeSolidStresssolver implicitly integratedwiththeFiniteVolumeFlowsolvertoanalyzetheacousticaldampingeffectsofflexiblematerials. The solid ismeshed in a similarway to the flow volumearound it.Built-inmeshingalgorithmsallowforconformalmeshingbetweenthefluidandsoliddomains.Themeshisallowedtodeflectifthedisplacementofthesolidissignificantcomparedwith the localgrid resolution.Momentumandenergyareexchangedbetweenthefluidandsolidsystems.Thisdirectlyaccountsforenergyextractionfromthefluidsystemtodeflectthesolidiftheconditionsareconducive.Threematerialtypeswereassessed:aluminum,PerspexandMDF(Multi-Density
wood Fibre). In the Finite Volume Solid Stress model, the Young’s modulus,
Poisson’sratioanddensitywerechangedaccordingtotherespectivematerial.
Theeffectsofthematerialpropertiesontheroofpaneldeflectionwerefoundto
besignificant.Perspexandplywooddeflectbyalmosttwoordersofmagnitude
morethatthebaselinealuminum.Asenergyabsorptionduetothemechanical
movement of the roof panel changes the perceived acoustic pressure at the
driver’searlocation,thisshowsthatthedriver’sexperiencewillbemuchquieter
withasunroofmadeofPerspexthanwithanaluminiumpanel.
Conclusion
By working closely with the transport industry, CD-adapco provides validated
tools to predict and design against aeroacoustical effects early in the design
process.One industrial aeroacoustics case study, among amultitude of other
possibleapplicationsinthetransportindustry,hasbeenbrieflydescribedinthis
article.Theresultsprovedtobeaccurateandthestudyhelpedillustratehowa
deeperunderstandingofacousticalphenomenacanbegainedthroughtheuseof
STAR-CCM+,therebyenablingahigherdegreeofengineeringvaluetobeadded
whilereducingcostsandtimescalesintheCAEprocess.
Formoreinformationaboutmethodologiesandbestpracticesforaeroacoustics
simulations in the automotive and aerospace sectors, please refer to [3,4].
Additionalcasestudiessuchastheairframenoisesimulationofacomplexnose
landing gear, the aeroacoustics study of an avionic cooling rack in an Airbus
cockpit,andtheanalysisofthefannoisesignatureinthepresenceofgustsare
alsodescribed.<
ABoVEImpactofthevortexontherearroofpanelbehindthesunroofopening
rIGHtModifiedSAEbodywithsunroofaperture,internalpassengercavityandflexibleroofpanel
i KEEPUPTODATEWITHTHELATESTSTAR-CCM+RELEASE: www.cd-adapco.com/products/star_ccm_plus
www.cd-adapco.com/industries/automotiveVisitthelinkbelowformoreAutomotivestories:
..::FeATURe ARTICleAeroacoustics
dynamics I S S U E 1 2 . 0 1 34
ABoVEInstantaneousvelocityfieldsurroundingthepanel:theflowishighlyunsteadyandleadstothegenerationofvortices.
ABoVERoofPanelDeflectionforthethreedifferentmaterials
ABoVEAcousticPressure(Pa)atthedriver’searlocationforthethreedifferentmaterials
ABoVEPressureSpectra(dB)atthedriver’searlocationforthethreedifferentmaterials.WithPerspex,thenoiselevelwhichthedriverhearsreducesbyupto10dB(decibels)atthepeakfrequencycomparedwithAluminium.Thisfigureillustrateshowtheflexibilityoftheroofpanelisabletoabsorbacousticalenergytoquietenthepassengerexperience.
ReFeReNCes:
[1] “InvestigationsofSunroofBuffetinginanIdealisedGenericVehicleModel--PartII:Numerical
Simulations”,M.Islametal.,presentedatthe29thAIAAAeroacousticsConference,May5-72008,
Vancouver,Canada,AIAA-2008-2901
[2] “NumericalandExperimentalInvestigationsoftheNoiseGeneratedbyaFlapinaSimplified
HVACDuct”,AnkeJägeretal.,presentedatthe29thAIAAAeroacousticsConference,May5-7
2008,Vancouver,Canada,AIAA-2008-2902
[3] “EfficientCFDSimulationProcessforAeroacousticDrivenDesign”,Mendonçaetal.,presentedat
theIISAEBrazilInternationalNoiseandVibrationCongress,October17-192010,Florianopolis,
Brazil,SAE-2010-36-0545
[4] “Aero-VibroacousticsFullyCoupledPredictionofPanelImpedanceEffectsinSunroofBuffeting”,
Mendonçaetal.,presentedatthe17thAIAA/CEASAeroacousticsConference(32ndAIAA
AeroacousticsConference),June5-82011,Portland,Oregon,AIAA-2011-2817
..::FeATURe ARTICle Automotive
dynamics I S S U E 1 2 . 0 135
Reducing the green house gases In therecentpast, thepublic’sattentionhasbecome increasinglydrawntotheconsequencesofenvironmentalpollutioncausedbytraffic.Inparticular,the influences of so-called “greenhouse gases” on the future climate havebeendiscussedintensively.TheEuropeanUnion,forexample,ispreparingarestrictionoftheCO2-carfleet-emissionof120g/kmby2012.Tomeetthesedemands, automive companies have been investing considerable effortstomaketheircarsmoreefficientand lessthirsty.Forgasolineengines,therecirculationofinertexhaustgasesandtheirmixingwithfreshairisanefficientmeasuretoreducethefuelconsumption.Unfortunately,thepresenceofinertgasesmakestheignitionofthemixturelessstable.Therefore,anoptimalcontrolofthein-cylinderflow,theturbulenceandthefuelpreparationintheengine’scombustionchambersisnecessarytoachievehighresidualgasrecirculationratesandthebestfueleconomy.ThisiswhereCFDcomesintoplay!
sTAR-CD and es-ice make the combustion chamber accessible
All the necessary models to simulate the turbulent flow field and mixturepreparationinthecombustionchamberareimplementedinSTAR-CD.Inthefollowing,theturbulentflowfieldwasmodeledwiththek-ε turbulence model forhighReynolds-numbersandthefuelinjectionwiththeLagrangianapproach.Inaddition,theexpertsystemes-iceallowsustheopportunitytocreatemovingmeshesthattakethemotionofthevalvesandthepistonintoaccount.Carehasbeentakentomodelthesparkpluginasmuchdetailaspossible,inordertoobtainaccurateresultsfortheflowfieldwherethesparkignitesthemixtureandtheflamepropagationstarts.The accompanying image shows typical results of a transient in-cylinder
simulation. The flow field during the engine’s intake stroke, aswell as thedistributionof fuel, residualgasandturbulence inthecombustionchamberatthetimewhenthesparkignitesthemixturecanbeobserved.Ontheotherhand,amoreunstablecombustioncanbeobservedattheenginetestbenchwhentheresidualgasconcentrationisincreasedandfinallyleadstomisfiring.Forapredictionoftheignitionlimit,andthereforethemaximumacceptableresidualgasrecirculationrate, it isnecessarytofinda“link”thatallowsaninterpretationofthemixturepropertiescalculatedwithSTAR-CDtoexplaintheunstablecombustionoberservedattheenginetestbench.
Turbulent and chemical scales characterize the premixed flame This link was found by analysing the turbulent and chemical scales forpremixed flames. A turbulent flow field consists of a variety of turbulentstructures, so called eddies, that influence the flame immediately afterignition. The big eddies, with a size larger than the thickness of theflame front, wrinkle and extend its surface. The small eddies, with a sizecomparable to the flame front thickness, penetrate the reaction zone andincrease the strain, species transport and heat flux. Both effects have acharacteristicimpactontheflamepropagationandextinction.
The development of internal combustion engines with lower emissions and fuel consumption requires an early knowledge of the combustion mechanisms. Therefore, a method was developed at the Inst i tute for Powertrains and Automotive Technology at the Vienna Universi ty of Technology that al lows the predict ion of the combustion stabi l i ty based on simulat ions with STAR-CD.
CFD Helps make engines more efficientThomas lauer - Vienna University of Technology, Austria
www.cd-adapco.com/industries/automotiveVisitthelinkbelowformorestorieslikethis:
the Vienna university of technology(TUVienna)islocatedintheheartofEurope,inacosmopolitancityofgreatculturaldiversity.Fornearly200years,theTUViennahasbeenaplaceofresearch,teachingandlearningintheserviceofprogress.TheTUViennaisamongthemostsuccessfultechnicaluniversitiesinEuropeandisAustria’slargestscientific-technicalresearchandeducationalinstitution.
..::FeATURe ARTICle Automotive
dynamics I S S U E 1 2 . 0 1 36
Thesecomplex interactionsandtheir influenceonthe ignitionstabilitycanbedescribed with dimensionless parameters, such as the Damköhler-number,which relates the turbulentandchemicalscalesandcanbederived fromthesimulationresultsoftheturbulentflowfield.Typicalinputdataarethepressure,thetemperature,theturbulentkineticenergy,theresidualgasconcentrationandthelocalair/fuelratio.However,tocomputethenumerousequationsefficiently,anautomatedpostprocessingwasnecessary.TheapplicationofSTAR-CDmacrofunctionality proved to be a goodapproach for this task. Thus, amacrowasdevelopedtocarryoutthenecessarycomputationsandtostoretheadditionaldatainfilesforfurtheranalysis. A limit for a stable ignition
By applying thismethodology to two gasoline engines with different injectionconceptsandin-cylinderflows,alimitforastableignitioncouldbedetermined.The dimensionless parameters that were derived from the simulation resultswere plotted in the BORGHI-diagram, which allows a visual representationof the premixed flame characteristics in relationship with the turbulent andchemicalscales(showninaccompanyingimage).ThestraightlinesofconstantDamköhler-andturbulentReynolds-numbersareincludedinthediagram. Allsimulationswerecarriedoutatanoperationpointwheretheenginesrevealed
a limitforastablecombustiononthetestbench.ItcouldbeshownthattheDamköhler-number describes the ignition limit satisfactorily. Itmust not dropbelowavalueof12.5to“keepthefireburning”inastableway.Acomparisonwithresultsfromtheenginetestbenchregardingthemaximum
acceptable residual gas recirculation rate that still enables a stable ignitionshowedagoodagreementwiththepredictionsofthenumericalmethod,asseeninthegraph.
Conclusion
A recirculationof residual gashelps to improve the fueleconomyof gasolineengines. Toachievea stable ignitionwithhigh residual gas concentrations inthe combustion chamber, a proper prediction of the numerous interactionsbetween the turbulent flowfield and the initial flame is necessary.Basedonthe simulation results from STAR-CD, dimensionless parameters have beencomputedtocharacterizethebehaviorofthepremixedflameafterignition.Themodelingcapabilitiesofes-iceandthemacrofunctionalityofSTAR-CDhelpedtosolvethistaskefficiently.Agoodcorrelationwithobservationsattheenginetestbenchwasfoundfortheallowableresidualgasrecirculationrates. Thus,STAR-CDcontributed toan improvementofengine’s fueleconomyandemissions.<
i FOR MORE INFORMATION ABOUT THE VIENNA UNIVERSITY OF TECHNOLOgY: www.tuwien.ac.at
ABoVEIgnitionlimitfortheinvestigatedenginesintheBORGHI-diagram
ABoVEComparisonofthemeasuredandpredictedresidualgasrecirculationrates
ABoVEResultsfortheturbulentflowfieldduringaspirationandignition
Turbocharger AnalysisDr. Richard Johns - CD-adapco
..::FeATURe ARTICle Turbomachinery
dynamics I S S U E 1 2 . 0 137
The accuracy of STAR-CCM+ enables the effects of a non-ideal inlet geometry to be compared with the uniform inlet flow condition.
..::FeATURe ARTICle Turbomachinery
dynamics I S S U E 1 2 . 0 1 38
Althoughrecoveryofexhaustgasenergyusingturbochargerswasfirstappliednearly100yearsagoandhasbeen inwidespreaduse intheheavy-dutydieselmarketever since, it isonly in recent years
thatturbocharginghasspreadtomassproductionvehiclesinsmallerengines.Thephenomenalmarketgrowth,firstinpassengercardieselenginesandmorerecentlyindownsizedgasolineengines,hasbeendrivenlargelybytheefficiencygains,andhenceCO2benefits,thatcanberealized.Plus,Formula1willbereturningtoturbochargingforthe2014season.
Modernturbocharging,however,ismuchmorecomplicatedthansimplyplumbinga turbocharger into the intakeandexhaustsystemand leaving it to its fate.Multipleturbos,variablegeometry,wastegate,bypassandintegrationintotheenginemanifoldandenginemanagementsystemcoupledwithhighoperatingtemperatures (>1,000°C in gasoline engines) in an already overcrowdedunderhood area provide serious challenges for powertrain, installation, andcalibrationengineers.
Toaddressthermo-fluid-structuralissuesrelatedtoturbocharging,CD-adapcohasdevelopedarangeofsolutionsusingSTAR-CCM+.Packagingconstraintsrarelyallowanideal,uniformflowentrytothecompressorandthiscanhaveadetrimentaleffectonthemap.
TheaccuracyofSTAR-CCM+enablestheeffectsofanon-idealinletgeometrytobesimulatedandcomparedwiththeideal,uniforminletflowcondition.Thisprovidesameanstoquicklyassessalternativeductingarrangementsandtheeffectoncompressorperformance.
Heattransferisamajorissueforturbochargedengines.Heattransferfromtheturbinetothecompressorisdetrimentaltoengineperformance,butheattransfer fromahot turboduringa transientoperation, forexampleakey-off
situationwhen there isno longeranyflow througheither thecompressororturbine,hasthepotentialtodamagenotonlytheturbocharger,butalsoothercomponentsintheunderhoodenvironment.Non-metalliccomponentssuchaselectricalconnectors,thewiringharness,rubbers,andcompositesareparticularlyvulnerable.ThepowerfulconjugateheattransfermodelingcapabilitiesavailableinSTAR-CCM+providesameanstosimulatethetransientflowandthermalfields,includingthestructure,withintheentireenginecompartment.Inturn,thisallowsaquickassessmenttobemadeastowhetherdamagewilloccurintheworstofsituations.
Lastbutbynomeansleast,high-frequencyturbochargernoisecanbeintrusivetooccupantsandthoseoutsidethevehicle,particularlyduringaloadchange.STAR-CCM+has a comprehensive capability to calculate the noise sourcesoriginatingfromtherotationoftherotoranditsinteractionwithothercomponentsanddeterminethesoundpressurelevelinthefarfield.<
i DR.RICHARDJOHNS,VICEPRESIDENTOFENGINEDEVELOPMENT,CD-adapcoEMAIL: [email protected]
Through the enhanced analysis capabilit ies of its STAR-CCM+ CFD software tool, CD-adapco is providing a boost to turbocharger technology in the 21st century.
dynamics I S S U E 1 2 . 0 139
The NASA C3X internal ly cooled turbine blade is a well documented [1] case for val idat ion of Conjugate Heat Transfer (CHT). The fol lowing analysis demonstrates two key features of STAR-CCM+: mult i-domain polyhedral meshing, which automatical ly bui lds continuous meshes between the sol id, external and internal f low volumes, and transit ion modeling, which enhances the predicted heat transfer distr ibut ion, especial ly on the blade suction side.
Several studies [2,3] using commercial codes have reported blade coolingvalidationresultsonaturbine.ThisarticledemonstratestheuseofSTAR-CCM+’capabilitiessuchaspolyhedralmulti-domainmeshingandtransitionmodelinginasimilarvalidationcase.Furthermore,due touncertainties in theexperimentalturbulencelevelsupstream,thesensitivityofthesurfaceheattransfertotheinletturbulenceviscosityratioisassessed.TheC3Xexperimentcomprisesofthreelinearcascadevanescooledinternally
by10circularparallelholesrunningthroughfromhubtoshroud;measurementsweretakenonthecentervane.Thepresentmethodologywasvalidatedagainstacaseoperatedatachord-basedReynoldsnumberof2.0million,withaninlettotalpressureandtemperatureof3.217barand783K,theexitMachnumberbeingmeasuredas0.9.The internalholesweresupplied independentlywithdifferentmassflowsforwhich,unfortunately,theinlettemperatureswerenotrecordedintheoriginalmeasurements.Thefigureontherightandtheaccompanyingtablesummarizethevanedimensionsandcoolingholes’inlettemperatures.
computational Setup The results from two different mesh types, a topologically block-structuredhexahedraandpolyhedra,werecompared.Inbothcases,sincethevanegeometryisalinearextrusion,20equallyspacedmeshlayerswereusedinthe7.62cmbetweenthehubandtheshroud.Allresultshereinarereportedforthemid-spansectionwheretheflowisnominallytwo-dimensionalandunaffectedbyend-walleffects.y+valueswerefoundtobelessthan1everywhereoverthevanesurfacefor
bothmeshes.Theinletandoutlettothedomainwereplaced14cmupstreamand
downstreamofthevaneleadingandtrailingedges,respectively.Bothhexahedralandpolyhedralmeshescontainjustover1millioncells(~800 kintheexternalflow,~150kinthesolidand~10kineachhole).Two turbulencemodelswere assessed. The first is a standard two-equation
k-ω-SST model, with implicit low-Re near-wall attributes but with no speciallaminar-to-turbulenttransitionfeatures.Thesecondcontainsacorrelation-basedmodification, referred to as the γ-Reθ model from Menter-Langtry (2004).
James Clement, Fred mendonça - CD-adapco
LEFt C3Xvanegeometryandcoolingholearrangementandinlettemperature
www.cd-adapco.com/industries/turbomachineryVisitthelinkbelowformoreturbomachinerystories:
..::FeATURe ARTICle Turbomachinery
ABoVEPressureandsuctionsurfacepressureprofiles,nontransitioncalculation,hexmesh,C3XCase1
Validation of blade Cooling on the NAsA C3X Turbine - polyhedral meshing & Transition modeling
ABoVE Mesh,domain,andnearwallresolutions
..::FeATURe ARTICleTurbomachinery
dynamics I S S U E 1 2 . 0 1 40
Atransportequation for intermittency, γ, tracks the likelihoodof theflowtobelocallylaminar(value0.0)orturbulent(value1.0)whereasthetransportequationforthetransitionReynoldsnumber,Reθ,usesexperimentcorrelationstofeedbacktotheγ-equationsourcetermswhenatransitionisadjudgedtooccur.Malan[4]haspublishedthetwoexperimentalcorrelationsusuallymissinginthestandardreferencestothemodel.Malan’scalibrationsareperformedonmanystandardtransitiontestcases,includingtheECROFTACT3-seriesandthefixedcorrelationsextensively validated on industrial cases. The inlet turbulence intensity in thisexperimentwassetto8.3%asrecordedintheexperiment.Theinletturbulencelength scale (inlet turbulence viscosity ratio) was notmeasured; therefore thisvalidationexercisetakestheopportunitytotestthemodelingsensitivitiestoinletturbulencelengthscales.
discussion of results The hexahedral mesh pressure coefficient over the pressure and suction surfaces compared favorably with the measurements and was insensitive to inlet turbulence length scales. The pressure profile was equally insensitive to the transition model in the polyhedral mesh. Conversely, the prediction of the wall heat transfer coefficient was found to be strongly dependent on the use/non-use of both the transition model and the inlet turbulence length scale.
The figure above left compares the non-transition/transition model heat transfer predictions on the hexahedral mesh. The transition model has the effect of suppressing the over-penetration of turbulence within the boundary layer; the effect at the leading edge is to reduce the heat transfer at the stagnation point. The levels here still continue to be higher than the measured values, but we shall see later that the heat transfer at stagnation is closely related to the upstream turbulence intensity.
The transition model clearly delays the onset of the boundary layer transition on the suction surface until around 40% of the chord, consequently reducing the wall heat transfer in line with the measurements. The predictive trend follows the
measured trend in the form of increasing heat transfer subsequent to transition, except that the transition length is predicted to be too short. in principle, the model correlation length [4] may be tuned to improve this predictive trend. On the pressure surface, the heat transfer levels are lowered consistently with the reduced levels at the stagnation point. The wiggles close to the trailing edge on both suction and pressure surface are a manifestation of the effect of the internal blade cooling holes.
The figure above right shows the sensitivity of the transition model predictions to the inlet turbulence viscosity ratio on the polyhedral. The main differences are observed in the shift of overall levels of wall heat-transfer below 50%, becoming relatively insensitive above 50% TVR.
conclusion We have demonstrated that there is sensitivity of the heat-transfer solutions to the levels of incoming turbulence. Therefore, it is very important to know the upstream turbulence levels from measurements as a requirement to perform well qualified CFD validation studies.
Furthermore, we have shown a validation of STAR-CCM+ for internally cooled turbine blades. Agile meshing capabilities using polyhedral cells for multiply-connected domains and advanced physics models cater for complex phenomena including surface heat transfer. The process affords significant productivity gains through integration and automation. <
i MOREINFORMATIONONTURBOMACHINERY [email protected]
ABoVENormalizedwallheat-transfer:no-transition(top),transition(bottom)
ABoVETransitionmodelnormalizedheat-transfersensivitytoinletturbulentviscosityratio,TVR:from40%to70%(bottom)
ReFeReNCes:
[1] HyltonL.D.,MihelcM.S.,TurnerE.R.,NealyD.A.,YorkR.E.,(1983),“AnalyticalandExperimental
EvaluationofthehHeatTransferDistributionovertheSurfacesofTurbinesBlades”,NASACR168015
[2] CanelliC.,SacchettiM.,TraversoS.,(2004),“Numerical3-DConjugateFlowandHeatTransfer
InvestigationofaConvection-cooledGasTurbineVane”,59CongressoNazionaleATI
[3] LuoJ.,RazinskiE.H.,(2007),“ConjugateHeatTransferAnalysisofaCooledTurbineVaneusingtheV2F
TurbulenceModel“,JournalofTurbomachinery,Oct2007
[4] MalanP.,SuluksnaK., JuntasaroE., (2009),“Calibrating theγ-ReθTransitionModel forCommercial
CFD”,AIAA-2009-1142-298,47thAIAAAerospaceScienceMeeting,Jan2009
..::FeATURe ARTICleTurbomachinery
dynamics I S S U E 1 2 . 0 141
CD-adapco has more than 30 years of expertise in developing cutting-edge simulation capabilities for the turbomachinery industry, the most notable and recent of which is the Harmonic balance (Hb) method. To understand the need for Harmonic balance, a little insight into the world of turbomachinery design with CFD is needed. Ingeneral, turbomachinerydevicesaremulti-stagewithunequalpitchesfor
statorsandrotors,andamajorityof theflowshighlyunsteady innature.Themost common simulation methodology is steady-state simulation, which iscomputationallyinexpensivebutintroducesapproximationsinthesolution.Eventhoughturbomachineryflowsareinherentlyunsteadyduetotherelativemotionofrotorsandstators,computinganunsteadysolutionisexpensiveandisoftenunsuitableinashortdesigncycle.Thechoicebetweensteady-stateandtransientmethodsdependsontherightbalancebetweencomputationalcost,accuracyandefficiency.Itisclearthattheturbomachineryindustrywouldbenefitfromabalancebetweenthetwoapproaches–acomputationallyefficientsolutionthataccountsfortheunsteadynatureoftheflow.ThenonlinearHBmethodisanentirelynewcomputationalapproach,offering
thebestofbothworldsspecifically forperiodicflows.Withapplications inthecompressible domain ranging from aerodynamics to blade-to-blade acousticinteractionsindevicessuchascompressors,turbines,fansandwindturbines,theHBmethodisacosteffective,accurateandefficientchoiceforunsteadyflows. Harmonic balance method Implementation in sTAR-CCm+ TheHBmethod inSTAR-CCM+ isa full decompositionof theNavier-Stokesequationsinthefrequencydomain.Theunsteady,transientflowisrepresented
inthefrequencydomainasaFourierseriesintime.Alltransportequationsformomentum,energyandturbulencearedecomposedintothefrequencydomainonthebasisoffundamentaldrivingmodes,usuallyablade-passingfrequencyor repeating wakemodes. Steady-state equations representing the unsteadysolutionatdiscretetimelevelsinasingleunsteadyperiodaresolvedtoobtaintheFouriercoefficients.Thenumberoftimelevelsrequireddependsonthenumberofmodesretained
intheproblem.Thesteadystatesolutionineverytime-levelisimplicitlycoupledattheperiodicboundariesbythephysicaltimederivatives.Thelinearsystemisthensubjectedtoapproximatefactorizationtoachieveimplicitcouplingbetweentimelevels.
Validation study ThenonlinearHBmethodimplementationinSTAR-CCM+hasbeenvalidatedrecently by numerical simulations of unsteady, rotor-stator interactions [1].The resultswerecomparedagainst those froma fullunsteady, time-accuratesimulationandfoundtobeaccuratewithsignificantsavings incomputationalcostandefficiency.Thevalidationwasconductedona2DcompressorstagemodelwiththreestatorbladestoeveryfourrotorbladesasdescribedbyEkiciandHall[2].Thefirststatorandsecondrotorofthefivestagesfromthisconfigurationwere considered and the computationalmesh, generated inSTAR-CCM+, isshownintheaccompanyingimage.Anaxialgapof0.25timestheaerodynamicchordoftherotorseparatesthe
twobladerowsandtheMachnumbersattheinletsofthestatorandrotorare0.68and0.71respectively.Astatic-to-totalpressureratioof1.2existsacross
Numerical Simulat ion of Turbomachinery f lows are among the most complex computat ions performed in the world of Computat ional Fluid Dynamics (CFD). CFD appl ied to Turbomachinery has come a long way from the inviscid 2D blade-to-blade methods of the 1960’s and recent developments have ensured that numerical simulat ion plays a major role in turbomachinery design.
Fred mendonça & prashanth shankara - CD-adapco
❐ FACT
Time saVing
The unsteady, time-accurate runs were computed
on a domain which included all three stator and
four rotor passages to satisfy periodicity of flow.
These runs took a total of approximately 20 hours
of CpU time. In comparison, the CpU time needed
for the Hb computations was less than one hour
retaining three harmonics at seven time levels.
That’s 19 hrs of savings in computational time for
a solution of reasonable accuracy for this case!
Harmonic balance method: A break From Traditional simulation of Turbomachinery Flows
www.cd-adapco.com/industries/turbomachineryVisitthelinkbelowformoreturbomachinerystories:
ABoVEInstantaneousPressureDistributionintheCompressorStagefromHBMethod
..::FeATURe ARTICleTurbomachinery
dynamics I S S U E 1 2 . 0 1 42
thestage.Complexperiodicityboundaryconditionsattheperiodicboundariesareappliedintherotationaldirection,whichenables the reductionofcomputations toasinglepassageineachrow,decreasingcomputationalcost.Thesolutions at all time levels are coupled to one anotherthroughtheseperiodicboundaryconditions.Theinletandoutletofthedomainarelocatedveryneartheleadingandtrailingedgesoftheoutermostblades.Theseboundariesaretreatedasnon-reflecting, farfieldboundaries, therebypreventingunsteadynumericaldisturbancesfromreflectingbackintothecomputationaldomainandreducingthesizeofthecomputations.Multi-stagecouplingbetweenrowsisachievedbyapplyinginter-rowboundaryconditionsattheinterfacesbetweenvariousrows.In the Euler computations from the HBmethod, one,
twoandthreeharmonicsareretainedforthebladepassingfrequencies in the stator and the rotor. A cell-centered,polyhedral-based, finite-volume discretization of thegoverningequationsisusedwithflux-differencesplittingandlinearreconstructionofvariables.Theaccompanyingimageshows the instantaneous pressure contours within thecompressorstagefromtheHBmethod,withcomputationsbeing carried out only on the center bladepassageandsolutions in theupperand lowerpassagephaseshifted,basedonthecenterpassage.
Results The comparison of the mean pressure distributions onthestatorandrotorfromthethreeHBcomputationswithresults fromthetraditional,unsteady, time-accuraterunsareshownintheimagebelowleft.Resultsfromasteadystatesolutionbasedonamixingplaneapproach,wherethe HB balance solver is used with zero harmonics tocomputetheflowthroughtwobladerows,arealsoshown.
The solution from the HB method agrees well with theunsteadysolution,whilethesteadystatesolutionhassmalldifferencesduetononlineareffects.Themagnitudeandphaseofthe1stmodeoftheunsteadypressure of the stator is also computed from the HBmethod.Theseresultsarecomparedwiththetime-domainsolutionsintheimagebelowcenter.Theunsteadypressurehasamagnitudeofabout10%ofthemeanandtheHBresultsvarybyonly2%ofthemean,suggestingthattheresultsshowgoodagreement.Similarcomparisonfortherotor(figurebelowright)showsthatthereismorevariationnear the trailing edge but the results are of reasonableaccuracy.Thus,theimplicitlycouplednonlinearHBmethodcan provide solutions of reasonable accuracy comparedto a time-accurate approach, while saving significantcomputationaltime.<
i SIMILARSTORIESCANBEDOWNLOADEDONOURWEBSITE: www.cd-adapco.com/downloads
ABoVEComputationalMeshforthe2-DCompressorStageinSTAR-CCM+
ABoVEMeanPressureDistributiononStator(top)andRotor(bottom)fromHBMethodandFull,UnsteadySolution
ABoVEMagnitude(top)&Phase(bottom)ofthe1stModeofUnsteadyPressureonStator–HBandTime-AccurateUnsteadySolutionComparison
ABoVEMagnitude(top)&Phase(bottom)ofthe1stModeofUnsteadyPressureonRotor–HBandTime-AccurateUnsteadySolutionComparison
ReFeReNCes:
[1] Weiss, J.M., Subramanian, V., and Hall, K.C., 2011, “Simulation of
Unsteady Turbomachinery Flows Using an Implicitly Coupled Nonlinear
HarmonicBalanceMethod”,GT2011-46367,June,2011.
[2] Ekici,K.,andHall,K.C.,2007.“NonlinearAnalysisofUnsteadyFlows
inMultistageTurbomachinesUsingHarmonicBalance”.AIAAJournal,45(5),
May,pp.1047–1057.
..::FeATURe ARTICle Aerospace
dynamics I S S U E 1 2 . 0 143
After evaluating a number of options, Raisbeck Engineering decided to invest in STAR-CCM+ due to its ability to address all of Raisbeck’s requirements.
RaisbeckEngineeringdesigns,developsandproducesuniquesolutionsthroughadvancedtechnologyandinnovativeengineeringthatenhancetheperformanceandoperationalefficiencyofaircraft. www.raisbeck.com
❐ FACTS
manufacturer Bombardier Aerospace
Class Twin-engine Corporate Jet
Crew 2
passengers Max. 8
propulsion 2 Turbofan Engines
max. Thrust 4,600 pounds (20.46 kN)
engine model Pratt & Whitney PW305A
engine power (each) 23,2 kN 5225 lbf
speed 887 km/h 551 mph
service Ceiling 15.545 m 51.000 ft
Range 4.441 km 2.760 mi.
empty Weight 6.641 kg 14.641 lbs
max. Takeoff Weight 10.659 kg 23.500 lbs
Wing span 13,40 m 44,0 ft
Wing Area 24,6 m² 265 ft²
length 17,80 m 58,4 ft
Height 4,36 m 14,3 ft
First Flight January 18, 1990
production status Still in production
INTeRNAlCabin length 17.67 ft 5.39 m
Cabin max. width 5.95 ft 1.81 m
Cabin width (floorline) 3.9 ft 1.19 m
Cabin height 5.71 ft 1.74 m
Floor area 68.9 ft2 6.40 m2
Total volume 453 ft3 12.80 m3
leARJeT 60 - speCIFICATIoNs
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A market study conducted by Raisbeck Engineering Inc. revealed that increased baggage capacity was the number one request from Learjet 60 operators. As a result, Raisbeck Engineering decided to pursue the opportunity of creating an Aft Fuselage Locker (AFL)
similar to the Raisbeck’s AFL for the Learjet 30-series aircraft.Six months before launching the Learjet 60 AFL program, Raisbeck Engineering
made a decision to stop outsourcing CFD and bring it in-house in an effort to expand hands-on knowledge, reduce development time, and increase control of priorities. After evaluating a number of options, Raisbeck Engineering decided to invest in STAR-CCM+ due to its ability to address all of Raisbeck’s requirements. After becoming familiar with the package, the next step for Raisbeck Engineering was to obtain a digital model of the Learjet 60 geometry.
Geometry To ensure the aircraft was accurately represented, Raisbeck Engineering invested in digitizing a full-scale Learjet 60. To accomplish the task, white light interferometry scanning was used. The technique involves projecting fringe patterns onto the aircraft from varying distances, capturing resulting interference patterns g
The Aft Fuselage Locker for the Learjet 60 marks a milestone for Raisbeck Engineering. The program is the f irst to use an in-house CFD capabil i ty at Raisbeck, and also the f irst Raisbeck product for the Learjet 60. For this program, a zero-drag penalty goal was set , achieved in simulat ions and val idated in f l ight test .
Designing a drag-free storage locker for the Learjet 60Davud Kasparov - Raisbeck Engineering Inc.
i DOWNLOAD THE LATEST AEROSPACE REPORT: www.cd-adapco.com/downloads/special_reports
ABOVELearjet 60 being prepared for white-light scanning with reference markers
and intensities with multiple cameras, and finally resolving the geometry byreducingdatainthefrequencydomain.Theresultingpointcloud,representinghalfoftheaircrafttoanaccuracyofunder0.01inches,consistedofover35millionpoints.Surfaceswere then lofted, conforming to the scandatawhilesimplifyingthegeometrybyexcludingminordetailssuchasrivets,gaps,smallantennas,etc.Withtheaircraftgeometryinhand,brainstormingcouldbegin.
Goals & Constraints Before the conceptual design of the aft fuselage locker (AFL) shape began,physicalconstraintswereset to,amongother things,ensure theAFLdidnotstrikethegroundduringtake-offrotation.Additionally,thetargetcargocapacitywas set at300 lbs and25 cubic feet.Most shapes considered for theAFLcouldbesplitinto3categorieswithvaryingdegreeofcargocapacity:thosethatendedwithafin,thosewithoutafin,andhybrids(seeimageforacomparisonoftheshapes).Witheachconcept,attributessuchascargovolume,externalwettedarea,andeaseofmanufacturingwereconsideredandweighedagainsttheresultsofCFDsimulations.
performance Toevaluatetheaerodynamicperformanceofeachconcept,arangeofcruiseconditionswaspickedfromtwosources,theaircraftflightmanualandoperatorfeedback.Ateachflightcondition,theaircraftwithaconceptshapeattachedwas trimmed in angle of attack for the target lift and with the incidence ofthehorizontal tail fora zeropitchingmomentabout itscenterofgravity. Theparametersummarizingoverallaerodynamicperformance,usedtocompareallconfigurationswithrespecttobaseline,wasthelifttodragratio,orL/D.Pressuredistributionsweremonitoredtoensurehighsuctionpeakswerenotintroduced,asshowninaccompanyingimage..
simulation Intermsofsimulation,allanalysiswasconductedinSTAR-CCM+.Simulationswere run in steady state with Menter’s SST K-ω turbulence model, whichpreviouslyhadbeenshown toproducegoodagreement in internal validationstudies.Inordertomeetstrictdeadlines,ameshconsistingofapproximately6.5millionpolyhedralcellswasusedtoenablethecalculationofatrimmedflightconditioninlessthan48hoursona24-nodecluster.
Results: CFD Analysisrevealedthatatallcruiseconditions,allconceptsshowedanabsolutechangeinL/Dof lessthan1%whencomparedtothebaselineconfiguration.Thiswaswithin the accuracy found in earlier validations.Out of curiosity, anaerodynamically dirty shape was simulated that showed a change in L/D of-4%(increase indrag).With theknowledgegained throughCFDsimulations,the design candidate with attributes of a large cargo capacity and a simplemanufacturingprocesswaschosentobeflighttested.
Results: Flight Test ThemaingoalofflighttestwastovalidatethezerodragoftheAFL.Asaresult,onlytheexternalshapeofthelockerwasrequired.Tobuildtheflighttestarticle,asingleblockofhighdensityfoamwasmachinedasamaster.Eightpliesofpre-impregnatedcompositewerethenlaidup,withhoneycombcoresandbulkheadsaddedincrucialareas,andcuredtoyieldashapemeasuring24feetinlength.FlighttestresultsindicatedthatSTAR-CCM+predictionsagreedwithinacceptableaccuraciestotheflighttestmeasurements,andthatthegoalofzero-dragpenaltywasachieved. Conclusions RaisbeckEngineeringhasdigitizedaLearjet60aircraft,designedadrag-freelockerwiththehelpofSTAR-CCM+andconfirmedresultsinflighttest.TheAftFuselageLockerfortheLearjet60isnowinthedetaileddesignphasewheretheinternalmechanics,manufacturing,andotherdetailsarebeingaddressed.When complete, this post-production and aftermarket modification will notonlyenableaircraftoperatorstocarrymorebaggagebutwillalsoenhancetheaircraft’sperformance.<
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ABoVELearjet60withRaisbeckAftFuselageLockeronfirstflight
BELoWLifttodragratiocomparisonbetweenCFDandflighttestresults
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BELoWCADmodeloftheRaisbeckAFLindetaileddesignphase
ABoVEGeneralizedAFLcandidateshapes,viewedupsidedown:finned(left),finless(center),andhybrid(right)
BELoWPressuredistributioncomparison,sideview:finless
locker(bottom)vs.baseline(top)atMach0.72.Someaircraftcomponentswerevisuallyomittedforclarity.
With the knowledge gained through CFD simulations, the design candidate with attributes of a large cargo capacity and a simple manufacturing process was chosen to be flight tested.
Fif teen weeks! That ’s al l i t took for a group of senior undergraduate students from the Universi ty of Washington’s Aerospace Engineering department to design, test , and bui ld a commercial qual i ty small Unmanned Aerial Vehicle (UAV) for research focusing on low-speed f l ight characterist ics and engine noise-shielding of supersonic f l ight vehicle configurat ions.
Dr. eli livne, professor of Aeronautics and Astronautics at the University of Washington, has been leading the senior capstone design project for more than a
decade with the help of Chester (Chet) Nelson, an Affiliate Associate professor and a boeing Technical Fellow. The motivation for the program was to provide students with ‘a complete, deep design experience’.
Inthe2010academicyear,thegoaloftheprojectwas to design, analyze, build, ground and flight testa UAV representing a commercial supersonic aircraftconfiguration, with focus on low speed handlingcharacteristics, low sonic boom design, and noiseshielding of the jet engine. Armed with just missionrequirementsandthedesignchallengesfor2010,theteamofseniorsfromtheAeronauticsandAstronauticsdepartmentoftheUniversityofWashingtonsurpassedallexpectationswithafinishedprototypethatwasoneofthemostcomplexandsophisticatedofitskind.Theprojectwascompletedwithinscheduleandtobudgetryconstraintsthatwouldimpressanyaerospaceindustryleader.
Students with no previous CAE/Testing/Manufac-turing experiencewere given fourmonths to developthe design into a flying prototype. If it soundschallenging, it is! The team of 32 seniors was splitintogroupswhichwere taskedwith:ComputerAidedDesign(CAD),aerodynamicsandComputationalFluidDynamics (CFD), wind tunnel testing, stability and
control, propulsion, acoustics, systems, structures,weight&balance,andconstruction.Over thecourseof the project, the students had the opportunity toexperienceandgaininsightintomajorelementsofthedesignprocessintherealworld:teamwork,informationexchange and communication, systems engineering,multidisciplinary interactions,andmore. Inshort, thiswas the complete aircraft design experience. TheUniversity of Washington’s program is also notablefor its industry participation. Local companies likeBoeing, Aeronautical Testing Service (ATS), Fiberlay,the University’s low speed Kirsten Wind Tunnel, andlocal model airplane experts participate and donatematerials,funds,timeandguidance. cFd in Early design Phase The focusof thisarticle is theCFDanalysis thatwasconductedaspartof theearlydesignphase.OneofthechallengesoftheCFDteamwastolearnthebasicsof CFD and how to use STAR-CCM+ to perform athorough computational analysis, providing inputs fortheinitialdesignandeventually improvingit.ThefactthatSTAR-CCM+isbotheasy-to-useandhasmanyautomation capabilities ensured bottlenecks in thesimulation processwere easily avoided. STAR-CCM+wasused fora seriesofplanformstudies, initially tofindthebaseplanformdesignthatwouldbeextensivelytestedinthewindtunnel.
Intotal,34differentconfigurationswereanalyzedfromatotalof274CFDrunsfor300totalmanhours
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From Design Challenge to Flying UAVs in Fifteen Weeksprashanth shankara - CD-adapco
p ABoVEInitialplanformdesignsstudied
p ABoVESTAR-CCM+resultsforCMvsalpha
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ABoVEPolyhedralmeshonfullmodelofaircraft
Why Study A&A at the uW?
The Aerospace Engineering industry is at the forefront of revolutionary technological developments intransportation,exploration,andnationalsecurity,withnewandsignificantchallengesemergingeveryday.
TheDepartment of Aeronautics and Astronautics at the University ofWashingtonwants to helpmeetthosechallengesbyofferingbachelor’s,master’sanddoctoraldegreesthatpreparestudentstobecomeleadersinthisexcitingfield.Ourprogramisattheforefrontofcurrentresearchinspace-basedinformationsystems, energetics, complex autonomous systems, composite materials, and more, ensuring ourgraduateswillbecompetitiveinacademicsandindustrywellintothefuture.
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ABoVEClvsalphafortheV-Tailconfiguration-ComparisonofSTAR-CCM+(CFD)andwind-tunnel(WT)results
ABoVECmvsalphainthefinalcruiseconfiguration-ComparisonofSTAR-CCM+(CFDCruise)andwind-tunnel(WTCruise)results
ABoVECdvsalphainthefinalcruiseconfiguration-ComparisonofSTAR-CCM+(CFDCruise)andwind-tunnel(WTCruise)results
and22,500computinghours.Theseareimpressivenumbers!AllCFDsimulationswereconductedona96coreLinuxclusteratATS.STAR-CCM+,CD-adapco’sfinitevolumebasedsolver,wasusedforsimulatingfluiddynamicsandtoproviderealisticinputstothedesignofthefinalmodel.Halfandfullmodelcaseswererunafterthepreliminaryplanformstudiestoselectthefinalconfiguration.Detailedsimulationswerethenruntodesigntheenginenacelle.
Design study Threeof the initial planformdesigns are shown (previous page),with the plate representing thetrunnionplateofthe2009UniversityofWashington’sCapstoneUAVwindtunnelmodel,whichwastobeusedasabasefortheplanformdesign.Thewingnamesrefertothesweepanglesoftheinboardandoutboardleadingedges,respectively.STAR-CCM+hasbeenextensivelyvalidatedforexternalaerodynamicsandthatconfidenceinthecodetranslatedtoinitialdesignstudiesbeingconductedsolelyinCFD.Apolyhedralmeshwascreatedforthehalf&fullmodelswithnearly1.3millionand4millioncells,respectively.Thek-є turbulencemodelwasused.Ofallconfigurationsstudied,the56-40planformwaschosenforfurtherstudyinthewindtunnel.TheCFDresults(accompanyingimages)showedthatthe56-40configurationhadapitch-upproblemfrom6to15degreesofangleofattackduetooutboardwingstalling.
Toeliminatethepitch-upproblem,twodifferentconfigurationmodificationswerestudied,thefirstinvolvingaddingachineandthesecondusingadogtoothwing.Althoughtheadditionofachinewastheoreticallyexpectedtoremovethepitch-upproblem,resultsfromSTAR-CCM+showedthatthechinecreatedavortexandoutboardwingseparationat12degreesangleofattack.At20degrees,theentireoutboardwinghadstalledandpartsoftheinboardwingshowedseparationtoo.Adogtoothwingwasattemptednextwith thedogtooth sized to7%of thewing chord. Thisdesign showedimprovements inpitchingand lift over thebase casebut still didn’t solve thepitch-upproblem.Eventually,thiswasleftforwindtunneltests.
Theimageopposite(middle)showstheCFDresultsforthe2010basecase,2010V-Tailplanformandthe2009windtunneldataforthe2009V-Tailconfiguration.Thefinaltaildesignforthe2010UAV included horizontal and vertical tails. Nearly 25 different configurations were simulated in
p ABoVEStreamlinesbehindthewings
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p ABoVE + BELoWStreamlinesfromSTAR-CCM+showingaircraftwithChineatdifferentanglesofattack
CFDtooptimizetheinitialwindtunnelmodel.Afterthewindtunneltestswerecompleted,thefinalconfigurationwassimulatedonceagainusingSTAR-CCM+.Theresultsofthisverificationsimulationshowedexcellentcomparisonwithwindtunneldataoverawiderangeofanglesofattackasseenintheadjoininggraph.ThecruiseconditionsoftheaircraftwerewellcapturedbyCFD.Finally,theeffectofwindtunnelwallswasalsosimulatedinSTAR-CCM+toallowcomparisonofwindtunnelandfreeflightcharacteristics.
OneofthemostimportantlessonslearnedfromtheCapstoneprojectwasthatCFDandWindTunnelTestingareintegralpartsofthedesigncycleandarecomplementarytoeachother.AlexLacomb,CFDLeadfortheprogram,said,
“STAR-CCM+hastheeasiestGUII’veexperiencedinaCFDcode,inadditionto the easy automated meshing which made the tool very valuable to thedesignteam.”TheaircraftwassuccessfullyflighttestedlastsummerandbearstestimonytotheexcellentworkofthestudentsattheUniversityofWashington’sDepartmentofAeronautics&Astronautics.CD-adapcoisproudtobeassociatedwithsucharewardingresearchprogramforundergraduatestudents.<
i MORE INFORMATION ON THE UNIVERSITY OF WASHINgTON’S ACADEMIC AEROSPACE PROgRAMS: www.aa.washington.edu/
What we couldn’t do in previous years of the program with other codes was made possible with STAR-CCM+. We were able to run hundreds of high-end CFD analyses in 4-5 weeks by a group of seniors who before that had had no experience with commercial CFD.
While 1D f low simulat ion software can accurately and rapidly simulate simple tasks, such as long straight runs, they are not adapted to complex 3D geometries such as separators, slug catchers and dry trees. Ful l 3D Computat ional Fluid Dynamics (CFD) codes, on the other hand, have the proven abi l i ty to accurately predict f low in these si tuat ions, al though typical ly at a much higher computat ional cost . Generat ing combined 1D/3D simulat ions promises the best of both worlds: by making i t possible to simulate complex systems of piping and equipment at a much higher level of accuracy than 1D-only simulat ions and in much less t ime than 3D-only codes, problems can be prevented earl ier in the design stage.
Challenges of deepwater drilling and productionAs the amount of oil and gas that can easily be produced hasdeclined, exploration and production companies have turnedtowards less accessible hydrocarbon sources including deepwater
andultradeepwaterbasins.However,thechallengesassociatedwithextractingoilandgasfromsuchenvironmentsareconsiderable.Tocitebutafew:waterdepth reaching3000metersandbeyond,higherpressuresofbothwell fluidsandoceanbottomwater, high temperatures ofwell fluids that can runup to300oF/150oCinnear-freezingoceanwater,muchlongerrunsofpipingandrisersback to production facilities and tricky ocean currents in deeperwater. Thesedifficultconditionscanleadtoflowassuranceproblemssuchassluggingandtheformationofhydratesandwaxyparaffinsinanenvironmentwhereremediationisfarmoreexpensiveandtime-consumingthaninnormaloffshoreconditions.
Advantages and limitations of 1D simulation toolsFlowassuranceanalysts typicallyuse1Dmodeling tools foranoverall viewofa field’s production scheme.1Dsimulation is used for sizingwell tubing, flowlines, and receiving facilities in order to maximize the initial production whileavoidingexcesssluggingandliquidsurgeslaterinthelifeofthefield.Multiphaseflowsimulationofthewellandpipelinenetworkwitha1DcodesuchasOLGAaddressesthermalinsulationandarrivaltemperaturerequirementsaswellasliquidinventories,flowpatterns,andpotentialforinstabilitiesinproductionsystems.Inordertoprovideusableruntimes,1Dsimulationhastraditionallyreduced
3Dmultiphaseflowtoasimplified1Dcomponent.Thisrequiresestimatingtheflowregime–forexamplestratified,annularorplug–historicallyaccomplishedbyconductingexpensivephysicalexperimentstoprovidethe1Dflowcoefficients.Theaccuracyofthe1Dsimulationisthuslimitedbythephysicalconditionsinwhichg
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Integration of 1D & 3D Flow simulation Helps meet Deepwater Flow Assurance Challenges Deborah eppel - CD-adapco
BELoWCooldownanalysisofasubseaChristmastree
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rIGHtPolyhedralmeshofasubseaChristmastree Fl
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p ABoVEAmalysisofaYjunctionwithtwovalves
AVeRAGe bReNT spoT pRICes EnERgy InFoRMaTIon aDMInIsTRaTIon anD BuREau oF LaBoR sTaTIsTICs
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theexperimentwasperformed;astheoilandgasindustrymovestoincreasingdepths,experimentsperformedatshallowerdepthsbecomelessandlessrelevant.Anotherconcernisthatthegeometriesofdeepwaterequipment
oftensurpassthelevelofcomplexitythatcanbesimulatedusing“off-the-shelf”componentsprovidedin1Dsimulationtools.Situations where the pipeline changes direction, meets up
with another pipeline, or flows into a resevoir all representinherent 3D problems. There are many others. Even in long1D pipes, flow conditions may arise, such as recirculatingflow in risers, that go beyond 1D’s predictive capabilities.In another example, gas lift is sometimes used by pumpingpressurized gas through the pipe to push the water forwardand prevent slugging, another inherently 3D phenomenathatcannotbeeasilymodeledwith1Dcodes. Increasing need for 3D simulation 3D simulation can address these issues thanks to its ability tosimulatemultiphaseflow ina3Denvironmentwithnoneed forassumptionsbasedonempiricaldata.ACFDsimulationprovidesfluidvelocity,pressure, temperature,gascomposition,andothervariables throughout the solution domain for problems withcomplex geometries and boundary conditions. As part of theanalysis,anengineermaychangethegeometryofthesystemortheboundaryconditionsandobservetheeffectofthesechangesonfluidflowpatternsordistributionsofothervariables,suchasgascomposition.CFD is becoming increasingly important in the deepwater
environment because engineers often have no empirical datato guide them. Several obstacles, however, have preventedengineersfromtakinggreateradvantageofCFD.Forexample,CFDsimulationsforthecomplexgeometriesfoundinsubseadrillingandproductioncanbecomputationallyexpensiveandusedtotakeanunacceptablylongperiodoftimetosolve.However,improvementsin solution algorithms and themove towards massively parallelhigh performance computing configurations have overcome thisobstacle.Anotherpotentialobstacle is thatengineerswant touseCFD
to simulate complex subsea equipment, but want to continuehandling simple geometries such as straight pipeline runs with
faster 1D codes. However, with the 1D and 3D software eachsimulatingspecificsectionsofthefluidflow,eachcodebecomesdependentupontheotherforinformationsuchasflowvelocities,flowrates,andpressuresattheboundariesbetween1Dand3Dsimulatedcomponents.In the past, this required a cumbersome process whereby
the analyst moved data back and forth between 1D and 3Dsimulations.Theanalystwouldfirstsimulatetheentiresystemin1Dwhileknowingthataccuracywouldsufferinthoseareaswherethe geometry is complex. Next, the analyst would extract flowconditionsat theboundariesof thegeometricallycomplexareasandusethemastheboundaryconditionsforthe3Dsimulation.The 3D simulation would provide much greater clarity into
whatishappeninginthecomplexareas.Thesechangeswouldofcourseaffectthe1Denvironmentandthe3Dresultswouldneedtobe re-entered into the1Dsimulationwhichwouldbe re-run.Depending on the stage in the design process and the level ofaccuracyneeded,severalmoreiterationsofmanuallyexchangingboundaryconditionsbetweenthe1Dand3Dsimulationsmightbeneeded.Alloftheseiterationswouldhavetoberepeatedforeverydesignchangeornewsetofoperatingconditions.
seamless integration between 1D and 3D simulation Therecentautomationofinformationexchangebetween1Dand3Dcodesgreatlyreducesthetimerequiredtoperformthistypeofanalysiswhile improving theaccuracyof the resultsbyprovidingseamlessflowofinformationbetweenthetwo.Themostprominentexample is the integrationofSTAR-CCM+withOLGA,a leading1Dcode.TheSTAR-CCM+usercanrunOLGAasaslaveprocesswhichcausesthetwocodestoexchangedataateachtimestep,muchmorefrequentlythanispossibleusingmanualmethods.Inatypicalexample,alongpipelinewasmodeledusingOLGA
whileSTAR-CCM+wasusedtosimulatethemultiphasetransientcharacteristics of the slug catcher at different flow rates andgas/liquid ratios. The analysis enabled engineers to successfullyoptimizethedesignoftheslugcatchertohandlethewiderangeofflowconditionsthroughouttheassetlife,therebygreatlyreducingtheriskofhavingtoreplaceitatapotentialcostoftensofmillionsofdollars.<
p ABoVEFlowstreamlinesaroundanoilrig
i MORE INFORMATION ON THE OIL AND gAS INDUSTRY: www.cd-adapco.com/industries/energy
The New state-of-the-Art in the America’s Cup DesignChasing The Wind
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ABoVEWave pattern at 11 knots
The America’s Cup is the oldest trophy in the world and the competing platform for the most advanced technologies in the marine f ield. In recent years, CFD has become the most powerful tool for both aero and hydrodynamic design. A research project steered by Dr. Ignazio Maria Viola shows how CFD can be appl ied to the design of an America’s Cup yacht.
Dr. Ignazio maria Viola, school of marine science and Technology, Newcastle University, and Dr. Raffaele ponzini, CIleA
The America’s Cup was sailed for the first time in 1851 at Cowes, Island of Wight, in conjunction with the largest exhibition ever held until then: the prince Albert’s Great london exhibition. The Americans took the opportunity to show their advanced
knowledgeofnavalarchitectureandbuilttheschoonerAmericafortheevent.Americawasdefinitivelyfasterthanthe14othercompetingBritishyachtsandwonthe“100GuineaCup,”whichwassubsequentlyrenamedtheAmerica’sCup.TheCupwasthendonatedtotheNewYorkYachtClubasatokenoftheirenthusiasmfor takingpart in internationalchallenges.For the following132yearsand24contests,theAmericansremainedtheundefeatedholdersofwhattheynowaffectionatelycalled“theAuldMug.”Since1983,however,theCuphasbeensuccessivelywonbyAustralia,USA,NewZealandandSwitzerland,beforefinallybeingbroughtbacktotheUSAin2010withtheSanFrancisco
YachtClub’svictoryof the33rdAmerica’sCup.Today, theAmerica’sCup istheoldesttrophyintheworldandthemostexpensivetowin.Eachchallengerspends tensofmillionsofdollars indesigning,building,andsailing itsboat,whichrepresentsthestate-of-the-artoftheworldwidemarineindustry.Windtunneltests,towingtanktestsandComputationalFluidDynamics(CFD)
are themain toolsused in thedesignofanAmerica’sCupyacht.However,whiletenyearsagoexperimentalinvestigationsweremuchmoreimportantthannumerical analysis, nowadays the situation is reversed. The ongoing growthof computational capabilities is increasing the usage of CFD even further.Commercial codes are becoming easier to use and allow more and morecomplexphysics tobemodeledand simulatedaccurately. For instance, thelaminarseparationbubbleontheleewardsideofthesails(whichisfollowedby the laminar-to-turbulent transition, reattachment and, finally, trailingg
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www.cd-adapco.com/industries/marineReadabouthowoursoftwareisusedintheMarineindustry:
rIGHt Simulatedbreakingbowwave
edgeseparation),thetransitiononthekeelandtherudder,orthedynamicbehaviorofyachtsinwaves,areallphysicsthatcanbemodeledbyCFDcodes suchasSTAR-CCM+.Suchnumericalcodeshavealsobecomemorereliableandaccurate.Tenyearsago, thedifferencebetweennumerical andmeasureddrag forabarehullwasoftheorderof10%,whileinthisproject,itwasfoundtobeoftheorderof1%forahullwithitsappendages.Theincrease inaccuracyhasallowedCFDtobeusedasareliabledesignandanalysistool.However, as with every very powerful tool, CFD must be
managedverycarefully.Wrongconclusionscaneasilybereached,therebyrequiringtheresultstobevalidatedagainsthighqualityexperimentaldata.Inparticular,awellset-upCFDanalysishastoproveitsabilitytopredicttheexperimentalresultswithoutknowingthembeforehand.In a recent research project [1] carried out in the Yacht
Research Unit of the University of Auckland (New Zealand)andcoordinatedbyDr. IgnazioMariaViola,twocandidatehulls(monohulls)designed for the32ndAmerica’sCupwere testedinatowingtankandanalyzedwithSTAR-CCM+.OnlythetowingtankdataofthefirstofthetwohullswasknownwhentheCFDanalysiswasperformed.Themeasuredsink,trim,andresistanceofthesecondhullwerepredictedbySTAR-CCM+withoutpriorknowledge of experimental data. The hulls weremodeledwiththekeelandtherudder,whichsignificantlyaffectedtheresultingpitchingmoment.Thelongitudinaltrimhadtobecomputedveryaccurately to predict the resistance correctly. The figures showtheverycloseagreementbetweenthecomputationalandexperi-mental results. In particular, the relative trim at different boatspeedswascomputedwithinanaccuracyoftheorderof0.01°,translatingintoanaccuracyintheresistancepredictionsoftheorderof1%–which,veryinterestingly,happenstobethesameorderofmagnitudeastheuncertaintyoftheexperimentaltests!This high level of accuracy could be achieved thanks to the
effortsofCD-adapco indevelopingareliableandaccuratetoolfor the marine industry: “STAR-CCM+ is the most advancedexistingcodetocomputehullperformanceanditrepresentsthestate-of-the-artfortheAmerica’sCupcommunity,”saidDr.Viola.Thecomputationwasrunonasimplemulti-coreworkstation.Thehullsweremodeledwithabout2millioncells.The6-DOFmodulewasusedtomodelthefreetosinkandtrimcondition.When thegridandnumerical set-upwere validatedagainst
experimentaldata,thehulldynamicbehaviorinwaveswasalsomodeled.
ThenextAmerica’sCupwillbesailedinmuchrougherconditionsthanwhatwehavebeenusedtosofarandsea-keepingwillbefundamentalforasuccessfuldesign.Theyachtswillberequiredtosailin30knotsofwind,therebyreachingveryhighspeedsindownwindconditions.Thisresultsinnewquestionsbeingraised:willwebeabletoperformexperimentaltestswithinthenecessaryaccuracy to validate CFD’s predictions? How will we measuredifferences in the hydrodynamic drag smaller than 1% in thetowingtankwhenwehavetomodel20-plus-knotsofboatspeedinwavescausedbya30-knotwind?Thechallengeisopen.TheonlycertaintysofaristhattheseconditionswillnotbeaproblemfortheengineeringsimulationsoftwareSTAR-CCM+.<
The America CraftedoncommisonbytheNewYorkYachtclubtocompeteagainstBritishsailboats(anintenserivalry),itwasto
sailthefirstinauguralyachtracearoundtheIsleofWightin1851,anevent
launchedbyPrinceAlberttopromotefriendlycompetitionbetweennations.
The‘America’(pictured above) wonthecompetitionsoconvincinglythattherace
wasnamedafterit.TheTimesreported:“offCoweswereinnumerableyachtsandoneveryside
washeardthehailistheAmericafirst?”Theanswer,“yes”;“Whatissecond?”
Thereply-“nothing.” Inthetellingandre-tellingofthis,
manybelievethatitwasQueenVictoriawhoposedthequestionanditwasa
signalmanwhoreplied,“Ma’am,thereisnosecond.”Thephraseisnowpartof
America’sCuplore. SothecupwonbyAmerica,becamethe
America’sCup. In1857,theownerspresentedthe
trophytotheNewYorkYachtClubasaperpetual“challengecupforfriendly
competitionbetweenforeigncountries.” www.americascup.com
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ReFeReNCes:
[1] ViolaI.M.,FlayR.G.J.,PonziniR.,CFDAnalysisoftheHydrodynamicPerformance
of Two Candidate America’s Cup AC33 Hulls, International Journal of Small Craft
Technology,Trans.RINA,inpress.
ABoVEThetwo1/4thmodel-scaleAmerica’sCupyachts(IACC-V5class)
ABoVEVertical height of the wave pattern at 11 knots for the full-scale model
i FORMOREINFORMATIONONTHEAMERICA’SCUPPLEASEVISIT: www.americascup.com
LEFtPressurecoefficientsubtractedfromhydrostaticpressure
ABoVENumericalandexperimentaltrimversusFroudenumber(boatspeedsfrom6to12knotsfullscale)
ABoVENumericalandexperimentalsinkversusFroudenumber(boatspeedsfrom6to12knotsfullscale)
ABoVENumericalandexperimentalresistanceversusFroudenumber(boatspeedsfrom6to12knotsfullscale)
..::FeATURe ARTICle Marine
dynamics I S S U E 1 2 . 0 1 58
..::FeATURe ARTICle Dr. Mesh
dynamics I S S U E 1 2 . 0 159
After a long sabbatical in my JAVA™ Hut cult ivat ing macros, I ’ve decided that i t ’s t ime I returned to my true vocation: sharing my incredible knowledge of meshing and post-processing in the pages of Dynamics magazine. (Al though to be honest, I ’d long since exhausted my supplies of SPF60 sunscreen, tropical-grade insect repel lent and surgical strength gin.)
For today’s tropic, I mean topic, I have a very excit ing subject in mind. Easy, but “oh-so-useful!” I am going to give you a step-by-step explanation of how to insert a 3D STAR-CCM+ scene into a PowerPoint presentat ion. Bringing your scenes to l i fe wil l help show your boss/col leagues/customers the phenomenon that you have just pinpointed in al l i ts 3D glory, while undoubtedly enhancing the qual i ty of your presentat ions.
dr. m
esh
HoW To: INseRT A 3D sTAR-CCm+ sCeNe IN A mICRosoFT poWeRpoINT pReseNTATIoN
sTep 1: Download and install sTAR-View+.
sTaR-View+ is a free, 3D interactive results viewer for sTaR-CCM+ which allows the user – whether he/she has a sTaR-CCM+ license or not – to “see” a sTaR-CCM+ scene in the same way as the engineer who created it. It is possible to zoom, pan and rotate the CaE stored model and post-processing data as well as show and hide features within the scene.When installing sTaR-View+, make sure that you select the option “Install sTaR-View+ office add-In.”
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The acclaimed return of Dr. Mesh
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i SEND ME YOUR THOUgHTS & SUggESTIONS FOR FUTURE DR. MESH ARTICLES: [email protected]
sTep 3: launch microsoft powerpoint.
you will notice a new tab called “CD-adapco” has been added.
..::FeATURe ARTICle Dr. Mesh
sTep 2: export the 3D scene that you want to share.
In sTaR-CCM+, right-click on the scene you want to save or on the name of the scene in the scene/Plot tree and select the option “Export 3D Visualization File.”
sTep 4: Insert the scene.
Click on “Insert a scene” in the “CD-adapco” ribbon and select the scene of interest.
sTep 6: slide show your presentation!
now, you can interactively translate and rotate the scene to expose its different angles. Please note actions such as zooming or hiding/showing parts are not yet available when using sTaR-View+ in Microsoft PowerPoint.
sTep 5: save your presentation.
save the presentation as a “PowerPoint Macro-Enabled Presentation.”
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Bring your results to life with the new, free, 3d interactive results viewer for star-ccm+
sTAR-CCm+ provides a free, stand-alone results viewer, sTAR-View+ that facilitates collaboration between engineering teams by giving everyone access to interactive visualization of the computed results. STAR-CCM+ allows users to distribute post-processed simulation results as “scene files” containing a three-dimensional representation of the stored CAE plot.
When viewed using STAR-View+, scene files allow the viewer to zoom, pan, and rotate the stored model and post-processing data as well as show and hide features within the scene. Now anyone, whether a STAR-CCM+ user or not, can have the luxury of fully exploring the solution. STAR-View+ is free to distribute and requires no license, which means that you can simply attach it to an e-mail with a selection of scene files.
Free download at: http://www.cd-adapco.com/downloads/star_view_plus/download.html
NB: follow the same steps in Microsoft Word if you wish to insert a scene into a text document.Until next time...
Right-click here
... or there
New “CD-adapco” tab
Right-click on the scene to reset it to its original view
..::ReGUlARsTraining
dynamics I S S U E 1 2 . 0 161
TRAINING VeNUesDetroit, United statesHouston, United statesseattle, United stateslondon, United KingdomNuremberg, Germanyparis, FranceTurin, Italybangalore, India
Training Courses
View your local course offerings, customer testimonials and register for an upcoming course at: www.cd-adapco.com/trainingTo Register for a Course: Complete the online registration: www.cd-adapco.com/training
Or request a faxable form from your training administrator: UsA: [email protected] (+1) 734 453 2100
UK: [email protected] (+44) 020 7471 6200 Germany: [email protected] (+49) 911 946433
France: [email protected] (+33) 141 837560 Italy: [email protected] (+39) 011 562 2194
specialized Courses:New specialized courses relating to application specific areas are developed throughout the year. Check for these courses at: www.cd-adapco.com/training
sTAR-Tutor Interactive / sTAR-Tutor on Demand:STAR-Tutor Interactive offers a broad range of tutorial and elective short courses which are delivered by our highly qualified support team via live streaming internet feed. These virtual classes extend and focus
knowledge built up from the Introductory STAR-CCM+ class to cover specific engineering analysis areas. For more information, please visit: www.cd-adapco.com/training/star_tutor.html
STAR-Tutor On Demand is a self-paced introductory training to the STAR-CCM+ process. Using a pre-recorded video of a support engengineer, STAR-Tutor On Demand offers engineers the ability to view a
complete STAR-CCM+ analysis from CAD import to post-processing in a single one hour session. For more information, please visit: www.cd-adapco.com/training/on_demand.html
Note: In most situations it will be possible to register trainees on the course of their choice. However, if requests for places on courses are received too close to the course date, this may not be possible.
Availability of places can be obtained online or by contacting your local office.
Training adds incredible value to the software you have purchased and comes highly recommended by all. Courses are regularly held at CD-adapco offices around the world including: Detroit, Houston, seattle, london, Nuremberg, paris, Turin and others. The courses listed on our website can be scheduled to suit your requirements. To take advantage of this, please request information from your local training administrator.
Courses are held in small groups and the number of available places can be checked online at: www.cd-adapco.com/training/multi_day.html
Just click on the course you are interested in to get an overview on the dates, locations, and availability. If the course of your choice isn’t scheduled in an office near you, then why not take it via Distant
Learning, CD-adapco’s new internet based remote learning service. To find out more or to get a course scheduled to suit your requirements please contact your local training administrator.
i CHECK OUT THIS LINK FOR COURSE AVAILABILITY: www.cd-adapco.com/training/calendar
Choose from the following courses: • JAVA™ Scripting - Process Automation
• STAR-CCM+ Wizard Creation
• Virtual Tow Tank
• Rigid Body Motion
• Vehicle Thermal Management (Incl. braking system analysis)
• Effective Heat Transfer
• Virtual Reliability Laboratory (Component Thermal Analysis)
• Computational Methods for Nuclear Engineering
• Advanced Engineering Optimization (Coming Soon) • Internal Combustion Engine Analysis course
• Turbomachinery Engineering (Coming Soon) • Applied Computational Combustion
• External vehicle aerodynamics (incompressible) (Coming Soon) • Aeroacoustics
• High Speed Aerodynamics (Coming Soon) • Energy Balancing for Buildings (Coming Soon)
• Fluid Dynamics for Biomedical Industry (Coming Soon) • Offshore Computational Engineering
• Battery Modeling
• Casting (Coming Soon) • Cabin Comfort Analysis (Thermal, Acoustic, HVAC systems)
• Fluid & Thermal Analysis for the Electronics Industry
• Computational Analysis of Wind Parks
• Wind Turbine Analysis (Coming Soon)
www.cd-adapco.com/trainingTrainingtofitintoyourschedule&yourlocation:
..::ReGUlARs Events
dynamics I S S U E 1 2 . 0 1 62
i FOR MORE INFORMATION ON OUR EVENTS: www.cd-adapco.com/events
events
www.cd-adapco.com/eventsBrowseourworkshops,conferences+webinars
The first ever sTAR Global Conference will be held in march 2012 in the Netherlands. Join engineers from around the world and explore the technology and techniques that will revolutionize your CAe process and empower you and your organization to successfully achieve your objectives.
mARCH 19-21 + FRee TRAINING! sTAR-CCm+ oRIeNTATIoN (ATTeNDees oNlY) Grand Hotel Huis ter Duin • Noordwijk • Netherlands
cd-adapco regularly participates in many global trade shows. to get the chance to talk in person with our experienced and friendly representatives, please make a note of our appearances at the confirmed shows below. For more information please contact our events staff: north America: tara Firenze - [email protected] Europe: Sandra Maureder - [email protected]
NoRTH AmeRICA
AIAA Aerospace sciences January 9-12, 2012 Nashville, TN
AAbC 2012 February 6-10, 2012 Orlando, FL
AsNe Day 2012 February 9-10, 2012 Arlington, VA
solidWorks World 2012 February 12-15, 2012 San Diego, CA
Renewable energy World Conference & exhibition 2012 February 14-16, 2012 Long Beach, CA
2012 sAe Hybrid & electric Vehicle Technology Display February 21-23, 2012 San Diego, CA
sAe 2012 World Congress April 24-26, 2012 Detroit, MI
AHs International 68th Annual Forum and Technology Display May 1-3, 2012 Fort Worth, TX
oTC 2012 May 1-3, 2012 Houston, TX
2012 Asee Annual Conference & exposition June 10-13, 2012 San Antonio, TX
AUVsI’s Unmanned systems North America 2012 August 7-10, 2012 Las Vegas, NV
battery power 2012 September 18-19, 2012 Orlando, FL
spe Annual Technical Conference and exhibition 2012 October 8-10, 2012 San Antonio, TX
eURope
WeAF Annual Conference 2012 February 22, 2012 Winter garden, UK
12th stuttgart International symposium 2012 March 13-14, 2012 Stuttgart, germany
sTAR GlobAl CoNFeReNCe 2012 March 19-21, 2012 Amsterdam, Netherlands
8th International Fluid power Conference IFK 2012 March 26-28, 2012 Dresden, germany
eWeA 2012 April 16-19, 2012 Copenhagen, Denmark
CompIT 2012 April 16-18, 2012 Luettich, Belgium
1st NAFems DACH Regional Conference May 8-9, 2012 Bamberg, germany
All energy 2012 May 23-24, 2012 Aberdeen, UK
power Gen europe 2012 June 12-14, 2012 Cologne, germany
Asme Turbo expo 2012 June 12-14, 2012 Copenhagen, Denmark
AAbC europe 2012 June 18-22, 2012 Mainz, germany
ACHemA 2012 June 18-22, 2012 Frankfurt, germany
2012 RAes Applied Aerodynamics Conference July 17-19, 2012 Bristol, UK
oNs 2012 August 28-31, 2012 Stavanger, Norway
smm 2012 September 4-7, 2012 Hamburg, germany
euromech 2012 - eFmC9 September 9-13, 2012 Rome, Italy
Follow us online.For more information: [email protected] www.cd-adapco.com
• STAR-CCM+ • STAR-CD • Engineering Services • Dedicated Support
simulation software for a New Frontier in engineering Innovation
