Performance Analysis of a Utility Helicopter with Standard ... · these UH-60ﬂight test data....

PerformanceAnalysisof a Utility Helicopter with Standard and AdvancedRotors

Hyeonsoo YeoRaytheonITSS

William G. BousmanArmy/NASA Rotorcraft Division

AeroflightdynamicsDirectorate(AMRDEC)US Army AviationandMissile Command

WayneJohnsonArmy/NASA Rotorcraft Division

NASA AmesResearchCenterMoffett Field,California

Abstract

Flight test measurements of the performance of theUH-60 Black Hawk helicopterwith both standard andadvancedrotorsarecomparedwith calculationsobtainedusingthe comprehensive helicopter analysisCAMRADII. In general, the calculatedpower coefficient showsgoodagreementwith the flight testdata. However, theaccuracy of thecalculationdegradesathighgrossweightfor all of the configurations. The analysisshows fairto goodcorrelation for collective andlongitudinal cyclicanglesand pitch attitude, and poor to fair correlationfor the lateral trim quantities (lateral cyclic angle androll attitude). The increasedsolidity of the wide chordbladeappearsto bea dominantfactorin theperformanceimprovement at high gross weight by reducing bladeloadingandthusdelaying stall.

Notation

��power coefficient��weightcoefficient

D fuselage dragM Machnumberq dynamicpressure� angleof attack�� aircraft pitchattitude� advanceratio solidity

Intr oduction

The ability to accurately predict the performanceof ahelicopter is essentialfor thedesignof future rotorcraft.Before prediction codescan be successfullyused, itis necessaryto assesstheir accuracy and reliability.

Presented at the American Helicopter Society Aerodynamics, Acoustics,and Test and Evaluation Technical Specialist Meeting, San Francisco,CA, January 23-25, 2002. Copyright c

2002 by the American

Helicopter Society International, Inc. All rights reserved.

Comparison of comprehensive analysis performancecalculations with helicopter flight testdatais crucial tosuchanassessment.

With the completionof recent flight tests,performanceand dynamic data are available for the standardUH-60 blades tested on a UH-60A airframe [1]; thestandardbladeson a UH-60L airframe[2]; andseveraldifferent versions of the wide chord blades on thesame UH-60L airframe [2]. These extensive flighttest data sets provide a valuable bench mark for theevaluation of comprehensive methods. In this study,performance calculations were carried out using theanalysisCAMRAD II andtheresultsarecomparedwiththeseUH-60flight testdata.

Flight TestData

Testdatawith the UH-60A standard(STD) blades wereobtained onaUH-60A airframe in theNASA/Army UH-60A Airloads Program conducted from August 1993toFebruary 1994[1]. Thetestaircraft, 82-23748, is asixth-year production aircraft. The data obtained from thetestarestoredin anelectronicdatabaseat NASA AmesResearchCenter. Thestandardbladeis constructed usinga titaniumsparwith afiberglassoutercontour. Thebladeusestwo airfoils, theSC1095andSC1094R8. Thisbladehasbeenusedon theBlackHawk over thelast25years.

The wide chord blade (WCB) is a development bladewhich hasan all composite graphite/glasstubular spar.The wide chord blade incorporatesan increasedchord(10% increaseof solidity), advanced airfoils (SC2110and SSCA09),and a swept-tapered tip with anhedral.Six configurationsor variantsof the wide chord bladehave beentested: configurations 1, 2, 3, 4, 4A, and5. The differences betweentheseconfigurations aremostly in the mid-spanand leading edgetip weights.All theresultsshown herearefor configuration4A. Thestandardandwide chordbladeplanforms areshown inFigure 1. The wide chord blade data usedhere wereobtained from a joint Sikorsky/Army feasibility flight

1

Report Documentation Page Form ApprovedOMB No. 0704-0188

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering andmaintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information,including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, ArlingtonVA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if itdoes not display a currently valid OMB control number.

1. REPORT DATE 2002 2. REPORT TYPE

3. DATES COVERED 00-00-2002 to 00-00-2002

4. TITLE AND SUBTITLE Performance Analysis of a Utility Helicopter with Standard andAdvanced Rotors

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S) 5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Army/NASA Rotorcraft Division,Army Aviation and MissileCommand,Aeroflightdynamics Directorate (AMRDEC), Ames ResearchCenter,Moffett Field,CA,94035

8. PERFORMING ORGANIZATIONREPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)

11. SPONSOR/MONITOR’S REPORT NUMBER(S)

12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited

13. SUPPLEMENTARY NOTES Presented at the American Helicopter Society Aerodynamics, Acoustics, and Test and EvaluationTechnical Specialist Meeting, San Francisco, CA, January 23-25, 2002

14. ABSTRACT Flight test measurements of the performance of the UH-60 Black Hawk helicopter with both standard andadvanced rotors are compared with calculations obtained using the comprehensive helicopter analysisCAMRAD II. In general, the calculated power coefficient shows good agreement with the flight test data.However, the accuracy of the calculation degrades at high gross weight for all of the configurations. Theanalysis shows fair to good correlation for collective and longitudinal cyclic angles and pitch attitude, andpoor to fair correlation for the lateral trim quantities (lateral cyclic angle and roll attitude). The increasedsolidity of the wide chord blade appears to be a dominant factor in the performance improvement at highgross weight by reducing blade loading and thus delaying stall.

15. SUBJECT TERMS

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as

Report (SAR)

18. NUMBEROF PAGES

26

19a. NAME OFRESPONSIBLE PERSON

a. REPORT unclassified

b. ABSTRACT unclassified

c. THIS PAGE unclassified

Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

test program conducted from November 1993 throughOctober1995(Appendix B of Ref. 2). The wide chordbladeswere testedon an aircraft 84-23953, which is aUH-60A upgradedto a UH-60L for testpurposes.

CAMRAD II Modeling

TheUH-60BlackHawk wasmodeledin CAMRAD II [3]as an aircraft with single main and tail rotors. Thecurrent model has beenupdated from a previous UH-60A study[4] usingCAMRAD II. TheUH-60A masterinputdatabaseis availableto qualified researchers.Minorchangeshave beenmadein chord length, quarter chordlocation, c.g. offset,pitch link geometry andthedetailedrepresentation of materialproperties. The SC1095andSC1094R8 airfoil decks aresameasusedin Ref.4.

The wide chord blade structural and aerodynamicproperties were obtained from Ref. 5. Section lift,drag,andmoment valuesfor the SC2110andSSCA09airfoils wereobtainedfrom airfoil C81decks developedby Sikorsky Aircraft.

The trim solutionusedin CAMRAD II is basedon theaircraftgrossweight,c.g.,flight speed,rotorrpm,density,and outsideair temperatureand solves for the controlsandaircraft attitudesthatbalancetheforcesandmomentswith zerosideslipangle. For the standardbladeon theUH-60A aircraft, the horizontal stabilatoranglewassetto matchthe measuredflight test valuesfrom the UH-60A AirloadsProgram. No equivalent measurementwasavailablefor theUH-60L testdatasothestabilatoranglewas set basedon Airloads Program measurementsatgiven

� �and � values. An aerodynamic interference

model in CAMRAD II was usedfor the performancecalculations. This includes the main rotor inflowinterferenceeffects on wing-body and tail and the tailrotor, as time-averagedwake-inducedvelocity changes.No empirical factorwasusedfor the calculationof theinterference.

The aerodynamiccharacteristicsof the UH-60 fuselageare basedon 1/4th scale wind tunnel tests reportedin Ref. 6. Only fuselagedrag value was updated toaccommodateconfigurationchanges.

FuselageDrag Configuration

The baselineUH-60A fuselagedragequations from thewind tunnel test[6] are:

� �� ft �� !�!" � � � # # � � � � Tail off� �� ft ��%$!$&� �� # � � � � # # � � � � Tail on

where q is dynamic pressure and �� is pitch attitudein degrees. The tail off configuration includesonly the

basicfuselageandthe tail on configuration includesthestabilator, vertical tail, andtail rotor headaswell. Thezeroangle of attackdragvaluedependsupontheaircraftconfigurationandtendsto increaseasnew modificationsaremadeto theaircraft. However, it is assumedthat themeasuredvariation of drag with angleof attack is notaffectedby theseaircraftconfigurationchanges.

Thereare four possibilitiesfor the equivalent flat platearea of the Airloads Program aircraft and these aresummarized in Table 1. These four cases differdepending upon both baselinedrag and the drag ofaircraftmodifications.Therearetwobaselinevaluesfor azeroangleof attackdrag. Oneis Sikorsky’s value,25.69ft � from their flight manualperformancesubstantiatingreport [7], which is the basicreferencefor the aircraft’shandbookperformance.Theothervalue,26.2ft � , is fromthestudyby Shanley [12], whichwasperformedunderaNASA contract.

The aircraft as testedin the Airloads Programdiffersfrom the baselinein two respects.First, the aircraft isa sixth-year production version and therefore includestheExternalStoresSupport System(ESSS)fairingsandmiscellaneous changessuchasa deicesystemdistributorassemblyandan ice detectorprobe. In addition, a wirestrike kit has beenaddedto this aircraft to upgrade itto fleet standard. Sikorsky [7] hascomputed the effectsof thesemodifications differently than the US ArmyAviation Engineering Flight Activity (AEFA) [9–11].Sikorsky’s estimateof the equivalent flat plate areaofESSSfairings, miscellaneous,and wire strike kit was0.78 ft � , 0.63 ft � , and 0.21 ft � respectively. AEFA’sestimate for those components was 2.5 ft � [9], 1.0ft � [10], 1.0 ft � [11]. Second,specificinstrumentationwasaddedto theaircraft for the testprogram. Thedragfor the BladeMotion Hardware (BMH), Low AirSpeedSensingand Indicating Equipment (LASSIE), and testinstrumentation wasdetermined by AEFA. The dragoftheRotatingDataAcquisitionSystem(RDAS) wasbasedon its projectedarea.

The equivalent flat plate areaof the Airloads Programaircraftwascalculatedbasedonthefollowing equation:

Airloads ProgramA/C = BaselineUH-60A (1st yearA/C) + ESSSfairing+ wire strike kit + misc.+ BMH/LASSIE + testinstrumentation+ RDAS

The four possiblecasesshown in Table1 are: (1) Case1 : Sikorsky’s baselinedrag+ Sikorsky’s dragbuild-up,(2) Case2 : Shanley’s baselinedrag+ Sikorsky’s dragbuild-up, (3) Case3 : Sikorsky’s baselinedrag+ AEFA’sdragbuild-up, and(4) Case4 : Shanley’s baselinedrag+ AEFA’s dragbuild-up. The final flat platearea,then,variesfrom 32.95 ft � to 36.34ft � . The current analysis

2

usesa zeroangleof attackdragvalueof 35.14 ft � for theUH-60A, whichis verycloseto theCase3 value.For theUH-60L, a flat plateareaof 35.04ft � wasused,asthisprovided the bestmatchof parasitedragat high speed.This valueis about 10% higherthanthe valuespecifiedby Sikorsky [2] for this configuration.Thefuselagedragequationsusedin thepresentcalculations are:

� ��'�ft �(�)�%*!"&�+�-,.�� /# � � � # # � � � �

for UH-60A (Airloads Program)� ��'�ft � �)�%*!"&� �0,.�� /# � � � # # � � � �

for UH-60L

Resultsand Discussion

UH-60A Performance

The total power coefficient for the UH-60A wascalculatedusing CAMRAD II and is compared withlevel flight data obtainedin the Airloads Program forsix weight coefficients in Figure 2. The total powercoefficient is the sumof eachengine’s power, basedonanengineoutput shafttorque sensorandtheoutputshaftspeed. The trim solution usedin CAMRAD II solvesfor the controls and aircraft attitudesthat balancetheforcesand moments in flight with zero sideslipangle.Performancewas calculatedusing nonuniform inflowwith a free wake geometry and a zero angleof attackdragvalueof 35.14 ft � . CAMRAD II calculatesonly themainrotorandtail rotorpower. Thusthefixedaccessorypower of 65.8 HP [7] was addedto the CAMRAD IIcalculations.

In general, the estimatedpower coefficient shows goodagreement with the flight test data. At low speeds( � 1 ��+� ), the analysis tends to underpredict thepower coefficient. The reasonsare threefold: (1)airspeedmeasurementsdegradeat lowerairspeedsasthedynamic pressureis reduced, (2) trim conditionsaremoredifficult to maintain,and(3) computedpower is stronglyinfluenced by induced power which is more sensitiveto wake effects. This correlation will be discussedquantitatively in the section“Quantitative PerformanceCorrelation.” As weight coefficient increases,largerdifferences are seen between the calculations andmeasurements.

Thecalculatedmainrotor power coefficient is comparedwith the measured value in Figure3. This is the samecalculationas in Figure 2, except that only main rotorpoweris compared.Main rotorpowercoefficient dataforthe UH-60A werecalculatedbasedon themeasurementof the main rotor torque. The analysisshows goodagreement with the flight test data. Slightly bettercorrelation is observedthanwith thetotalenginepower.

Figure 4 compares the calculatedtail rotor power withthe test data. Tail rotor power coefficient data werecalculatedbasedon themeasurementof theintermediateshaft torque. The analysisunderpredictsat low speedsandoverpredictsat moderatespeedsup to

�2�of 0.0091.

However, an overprediction is observed at all speedsat��of 0.010 and0.011. Tail rotor power is sensitive to

theaircrafttrim, in particular, thesideslipangle,andthiswill beexaminedin thenext section.

Trim Effectson UH-60A Performance

The trim results at��

of 0.0065 (�3� � = 0.08)

are investigated in detail in Figures 5 through 8.Aircraft attitudesandpilot control anglesareshown inFigure 5. The analysisshows fair to good correlationfor collective and longitudinal cyclic anglesand pitchattitude. However, a large difference is observed inthe lateral trim quantities (lateral cyclic angleand rollattitude). Within the datascatter, the flight datawereobtained for a zero roll angle, that is, no steadylateralaccelerationon the pilot. To accomplish this, the pilottendsto fly with a small amount of sideslip and usesthe aircraft’s staticdihedral to zero the roll angle. TheCAMRAD II trim for �54 �6� $ is clearly outsidethisscatter.

Figure 6 shows blade flap and lag hinge rotationangles. The calculatedconing anglesare comparedwith measuredvalues from blades1 and 2. Steadyconing can also be derived from the blade thrust andthe centrifugal force (70,883 lb.). The calculatedconing anglesshow good agreement with CAMRAD IIestimatedvalues. Thus, it is concluded that therewasa bias error in the coning angle measurements. Thecalculatedmeanlagangleshowsgoodcorrelationat �870.3, considering the scatterof the measured data. Athigher speeds,however, the measured data agree wellwith eachotherandtheanalysisshowsanoverprediction.The calculatedlongitudinal flapping anglesshow goodcorrelation up to � of about0.2, but overpredictasspeedincreases.CAMRAD II capturesthesuddenincreaseofthe longitudinal flapping angleat � = 0.35. However,the analysisshows a muchlarger change thanthe data.The analysis underpredicts lateralflappinganglesat allspeeds.This is similar to thepoor lateraltrim predictionsshown in Figure5.

The calculatedmain rotor shaftpitch androll momentsarecomparedwith flight testdatain Figure7. Thetrendis thesameasthelongitudinalandlateralflappingangles.

The calculated tip path plane angles in an inertialcoordinate systemare comparedwith measured valuesin Figure8 to seethe combined effects of a rotor andafuselage.Thetip pathplanetilt anglesaredefinedas:

3

Longitudinal TPPtilt angle= 9;:=< (longitudinal flappingangle) > aircraft pitchattitude ��*@? shaftpre-tiltLateral TPP tile angle= 9�: � (lateral flapping angle) >aircraftroll attitude

The longitudinal tip path plane tilt anglesshow goodcorrelation at all forward speeds.This resultshows thatthe rotor propulsive force, thusthe airframe dragvalue,is accurate.However, thereseemsto be an inaccuracyin the lift and pitching moment of the fuselage andstabilator. Thecalculatedlateraltip pathplanetilt anglesshow good correlation up to � of around 0.2 and thenoverpredictasspeedincreases.Although thecorrelationappears to be better than with roll attitude, there stillmay be uncertainties other than fuselageaerodynamiccharacteristics.

To understandthepoorto fair correlation of thetail rotorpower andlateral trim values,the effect of sideslipwasevaluated by looking at changesof A 5 degrees. Thesechanges have little influenceon the main rotor powerandlongitudinal TPPtilt angle. As shown in Figure9,however, a > 5 degreesideslipangletrim slightly reducesthe tail rotor power at moderateand high speeds,andthusimprovesthecorrelation. However, theaircraft rollattitudeis increasedsignificantlyso that the lateralTPPtilt angleis far from the flight test data. A � 5 degreesideslipangletrim shows bettercorrelation for the rollattitudeandlateralTPPtilt anglebut overpredicts thetailrotor power at moderate and high speeds. The lateralflappingangleshows no sensitivity to the sideslipanglechange.

The effect of a main rotor to airframe aerodynamicinterferenceon the performanceand longitudinal trimvaluesis shown in Figure10. Themainrotor to airframeinterference has a small influence on the main rotorand tail rotor power required. The pitch anglesareslightly underpredictedatmoderateandhighspeedrangewithout interference. The longitudinal flapping angles,however, show good correlation without interferenceeffects,especiallyat �84 0.2.

The effect of a fuselage flat plate areachanges on thepower coefficient andlongitudinal trim values is shownin Figure 11. A 10% change of the flat plate areafrom the baselinevaluechanges the required power bya maximum of 6.5%. A 10% reduction of the fuselagedrag shows good correlation for the longitudinal TPPtilt angle. However, the pitch attitudeand longitudinalflappingangleshow largerdeviations at highspeeds.

STD/UH-60L and WCB/UH-60L Performance

The total power coefficient ( B� � ) for the STD/UH-60Lis calculatedandcomparedwith level flight testdatain

Figure12. Thetotal powercoefficient is thesumof eachengine’s powerandit is normalized to protectSikorsky’sproprietary data. The standardblade was testedon aUH-60L, aircraft 84-23953, as part of the developmenttestingof the wide chordblade. The only differenceinmodeling betweentheUH-60A andtheSTD/UH-60Listheflat plateareaof the fuselage. Thecalculatedpowercoefficient for the STD/UH-60L matchesthe measuredvaluesquite closely. Figure13 comparesthe calculatedperformanceof the WCB/UH-60L with flight testdata.Thenormalizedpowercoefficient ( C� � ), whichis differentfrom B� � used for the STD/UH-60L, is used for thiscomparison. The analysis shows good correlation upto a weight coefficient

�3� � �� . However, anunderprediction is observed at high gross weight andspeed.Thesecorrelationswill bediscussedquantitativelyin thenext section.

CAMRAD II was usedto investigatethe effectsof thenew airfoils alone and combined with the increasedsolidity. Figure 14 shows the anglesof attack versusMachnumber at

�3�= 0.011 and � = 0.24. Thesevalues

are calculatedfrom CAMRAD II and plotted at threedifferentspanwiselocations (r/R = 0.5,0.7,and0.9)andat every 15 degree azimuthangle. At this high grossweight condition, most of baselineblade experiencesstall on the retreatingside. The addition of the newairfoils to the standardbladehaslittle influence on theangleof attackdistribution, andthusstall characteristics.However, thewidechord blade, dueto increasedsolidity,reducesbladeloading andthusdelaysstall inceptionatthis highweightcoefficient.

QuantitativePerformanceCorr elation

To characterizethe accuracy of the correlation, theperformance data have been examined quantitatively.Figures 15 through 17 compare the calculated andmeasuredperformance of the UH-60A. Only data for�ED ��+� � is includedin Figure15. The45 deg diagonalline representsaperfectmatchbetweenanalysisandtest.The calculatedpower coefficients lie above the 45 degline if the analysisoverpredicts, and below the line iftheanalysisunderpredicts.Thecorrelation is assessedbyfitting a leastsquaresregressionline andcomputing theslope,m. A secondmeasureis thecorrelationcoefficient,r, which provides an indication of dispersion. A thirdmeasureis theRMSerrorfrom the45deg line. A similarapproach can be found for the harmonic correlationfor oscillatory flap bending moment by BousmanandMaier [8]. CAMRAD II shows goodcorrelationat �FD��+� � . Excluding

� �of 0.011 which hasfew datapoints,

theworstvaluesare:m= 1.060, r = 0.970,andRMSerror= 4.6508E-5. Estimatedpower is underpredicted at lowspeed( �G7 �6�H�!� ) except

� �of 0.01, thusboth m and

4

r aresignificantlylessthanunity asshown in Figure16.Themainrotor powercorrelation showsbetteragreementthanthe total enginepower (Figure 17). Excluding

�I�of 0.011, theworstvalues are:m = 1.045, r = 0.990, andRMS error= 3.4586E-5.

The STD/UH-60L correlation also shows goodagreement as in Figure 18. The analysisappears toslightly overpredict at moderate speeds,as was seenwith the UH-60A prediction. However, the analysisshows good correlation at moderate speeds in theWCB/UH-60Lcaseasshown in Figure 19.

In general, CAMRAD II underpredictsperformanceathighgrossweightandhighspeed.Thus,theslopedepartsfrom1,although thecorrelationcoefficientindicateslittledispersion. The m, r, and RMS error values for thethreeaircraftsare tabulatedin Table 2 and also shownin Figure 20. The scaleof RMS error values of theUH-60L correlationis different from that of the UH-60A correlation due to the normalizationof the powercoefficients for UH-60L.

The ability of the analysisto predict the performancedegradesfor all the configurationsas the grossweightincreases. To understand the performance predictiondegradationat high grossweight, theeffectsof dynamicstall (Leishman-Beddoesmodel) on the performancewere investigated for the wide chord blades. Theparameters required for the Leishman-BeddoesmodelwerecalculatedusingCAMRAD II becausetest valueswerenot available. The calculationwith dynamic stallshowedminoreffectsat moderatespeedwhile thepowerwasslightly reducedat highspeed.

Conclusions

The analysisCAMRAD II hasbeenusedto predict theperformanceof the UH-60 Black Hawk helicopter withstandardand advanced rotors. The analysis has beencorrelatedwith theflight testdatabothqualitatively andquantitatively. Fromthis studythefollowing conclusionsareobtained:

UH-60A

1. The predictedtotal engine power and main rotorpower show good agreement with the flight testdataat �JD ��+� � . However, an underpredictionis observedat �87 �6�H�!� .

2. The analysisshows fair to good correlation forcollective andlongitudinal cyclic anglesandpitchattitude and poor to fair correlation for thelateraltrim quantities (lateralcyclic angleandrollattitude).

3. The tip path plane tilt angles in an inertialcoordinate system show that there seems tobe an inaccuracy in the fuselage longitudinalaerodynamic characteristics.Although sidesliphasa significantinfluence on the tail rotor power andtheaircraft roll attitude,noconsistentimprovementis obtained.

STD/UH-60L and WCB/UH-60L

1. The analysisshows the sametrends as the flighttestdata.However, anunderprediction is observedfor the performanceof the WCB/UH-60L at highgross weight and speed. The degradationof theability of theanalysisto predict theperformanceathigh grossweightoccursfor all theconfigurationscalculated.

2. Increasedsolidity of thewide chord bladeappearsto be a dominant factor in the performanceimprovement at high gross weight by reducingbladeloadingandthusdelaying stall inception.

Acknowledgment

The authors would like to expressthanksto Dr. JohnBerry, Mr. JamesO’Malley, andMr. DouglasA. EhlertatUSArmy AMCOM andMr. T. Alan Egolf atSikorskyAircraft Corporation for their sharing of valuabledataandknowledge.

References

[1] Kufeld, R. M., Balough, D. L., Cross, J. L.,Studebaker, K. F., Jennison,C. D., andBousman,W. G., “Flight Testing of the UH-60A AirloadsAircraft,” American Helicopter Society 50thAnnual ForumProceedings,WashingtonD.C.,May1994.

[2] Bednarczyk, R., Boirun, B., DiPierro, A.,Fenaughty, R., Sheets,F., Trainer, T., and West,A., “Growth RotorBladeFeasibilityDemonstrationFlight TestReport,” SER702183, May 1996.

[3] Johnson, W., “Rotorcraft AerodynamicsModelsfora Comprehensive Analysis,” AmericanHelicopterSociety 54th Annual Forum Proceedings,Washington, D.C.,May 1998.

[4] Kufeld, R. M., and Johnson, W., “The Effects ofControl SystemStiffnessModelson the DynamicStall Behavior of a Helicopter,” Journal of theAmerican Helicopter Society, Vol. 45, No. 4,October2000.

5

[5] Mudrick, M., “Main Rotor SystemLoads,” SER702603,September1999.

[6] Bernard, R., “YUH-60A/T700 IR SuppressorFullScale Prototype Test Report,” SER 70094, June1976.

[7] Boirun, B., “Flight Manual PerformanceSubstantiating Report for the UH-60A HelicopterBasedon the Multi-Year II Configuration,” SER70279-1,May 1988.

[8] Bousman, W. G.,andMaier, T. H., “An Investigationof Helicopter Rotor Blade Flap Vibratory Loads,”American Helicopter Society 48th Annual ForumProceedings,Washington,D.C.,June1992.

[9] “UH-60A External Stores Support System FixedProvision Fairings Drag Determinations,” FinalReport,USAAEFA ProjectNo. 82-15-1,May 1984.

[10] “Airworthiness and Flight CharacteristicsTest ofa Sixth Year Production UH-60A,” Final Report,USAAEFA ProjectNo. 83-24, June1985.

[11] “BaselinePerformanceVerification of the12thYearProduction UH-60A Black Hawk helicopter,” FinalReport,USAAEFA ProjectNo.87-32,January1989.

[12] Shanley, J.P. “Validationof UH-60A CAMRAD/JAInput Model,” SER701716,November1991.

Table1 Flat plateareacalculation

EquivalentFlat PlateDrag(sq. ft.)Case1 Case2 Case3 Case4

BaselineUH-60A 25.69[7] 26.2[12] 25.69[7] 26.2[12]

ESSSfairing 0.78 0.78 2.5 2.5wire strikekit 0.21 0.21 1.0 1.0

misc. 0.63 0.63 1.0 1.0

BMH/LASSIE 2.0 2.0 2.0 2.0

testinstrumentation 0.83 0.83 0.83 0.83

RDAS 2.81 2.81 2.81 2.81

UH-60A (Airloads program) 32.95 33.46 35.83 36.34

6

Table2 Slope,correlation coefficient,andRMS errorvalues

UH-60A UH-60A��m r RMS m r RMS

( �KD �H�!� ) ( �87 �+� � )0.0065 1.015 0.995 2.0225E-5 0.436 0.944 6.2228E-5

0.0074 0.993 0.995 2.8172E-5 0.344 0.916 8.1571E-5

0.0083 1.060 0.994 2.2579E-5 0.907 0.844 7.1231E-5

0.0091 1.052 0.970 4.0415E-5 0.432 0.956 15.240E-5

0.010 1.027 0.992 4.6508E-5 0.459 0.593 6.1474E-5

0.011 0.832 0.867 3.0164E-5 N/A N/A N/A

UH-60A (MR)� �m r RMS

( �KD �H�!� )0.0065 1.042 0.997 1.4217E-5

0.0074 0.987 0.997 1.2302E-5

0.0083 1.045 0.995 2.9285E-5

0.0091 1.030 0.975 3.4586E-5

0.010 1.018 0.990 1.9127E-5

0.011 0.821 0.908 4.3542E-5

STD/UH-60L WCB/UH-60L��m r RMS m r RMS

0.0065 1.093 0.994 0.021069 1.048 0.996 0.022893

0.0081 1.003 0.988 0.017743 0.987 0.993 0.017304

0.0085 1.034 0.991 0.015666 0.905 0.990 0.017643

0.0091 1.040 0.999 0.057867 0.875 0.995 0.015197

0.010 0.848 0.973 0.026714 0.682 0.990 0.039625

0.011 0.498 0.984 0.053192 0.583 0.966 0.066199

7

- 3 0- 2 0- 1 0

01 0

0 0.1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 1

in.

r /R

Elastic axis

Quarter chord

C.G. axis

SC1095 SC1094 R8 SC1095

(a) Standardblade

- 3 0- 2 0- 1 0

01 0

0 0.1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 1

in.

r /R

SC2110SSCA09

(b) Wide chordblade

Fig. 1 UH-60BlackHawk rotorbladeplanform

8

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

CP

µ

(a) LNMPORQ�S QTQTUTV

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 84

CAMRAD II

CP

µ

(b) LNMPO'Q�S QTQXWZY

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 88

CAMRAD II

CP

µ

(c) L M ORQ�S QTQT[T\

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 89

CAMRAD II

CP

µ

(d) L M O'Q�S QTQT]�^

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP

µ

(e) L M O Q�S Q�^=Q

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP

µ

(f) L M O'Q�S Q�^T^

Fig. 2 Calculatedandmeasured power coefficient for UH-60A (Airloads Program)

9

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

CP MR

µ


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 84

CAMRAD II

CP MR

µ


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 88

CAMRAD II

CP MR

µ

(c) L M ORQ�S QTQT[T\

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 89

CAMRAD II

CP MR

µ


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP MR

µ


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP MR

µ


Fig. 3 Calculatedandmeasuredmainrotorpowercoefficient for UH-60A (AirloadsProgram)

10

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

CP TR

µ

(a) L M ORQ�S QTQTUTV

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 84

CAMRAD II

CP TR

µ

(b) L M O'Q�S QTQXWZY

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 88

CAMRAD II

CP TR

µ

(c) LNMPORQ�S QTQT[T\

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 89

CAMRAD II

CP TR

µ

(d) LNMPO'Q�S QTQT]�^

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP TR

µ

(e) L)MPO Q�S Q�^=Q

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 90

CAMRAD II

CP TR

µ

(f) L)MPO'Q�S Q�^T^

Fig. 4 Calculatedandmeasuredtail rotorpowercoefficient for UH-60A (AirloadsProgram)

11

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD IIC

olle

ctiv

e an

gle

(deg

.)

µ

(a) Collective angle

- 8

- 4

0

4

8

1 2

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Pitc

h a

ttitu

de

(d

eg

.)

µ

(b) Pitchattitude

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Late

ral

cycl

ic a

ngle

(de

g.)

µ

(c) Lateral cyclic angle

- 8

- 4

0

4

8

1 2

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD IIR

oll

attit

ude

(deg

.)

µ

(d) Roll attitude

- 1 6

- 1 2

- 8

- 4

0

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Long

itudi

nal

cycl

ic a

ngle

(de

g.)

µ

(e) Longitudinalcyclic angle

- 1 0

- 5

0

5

1 0

1 5

2 0

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Sid

eslip

ang

le (

deg.

)

µ

(f) Sideslip angle

Fig. 5 Aircraft attitudeandpilot control anglesfor UH-60A at�_� �`�6� �!� #a"

12

0

2

4

6

8

1 0

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)Coning needed to match blade thrustCAMRAD II

Con

ing

angl

e (d

eg.)

µ

(a) Coningangle

- 6

- 4

- 2

0

2

4

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)CAMRAD II

Mea

n la

g an

gle

(deg

.)

µ

(b) Meanlag angle

- 2

0

2

4

6

8

0 0.1 0 .2 0 .3 0 .4


Long

itudi

nal

flapp

ing

angl

e, β

1c (

deg.

)

µ

(c) Longitudinal flappingangle

- 2

0

2

4

6

8

0 0.1 0 .2 0 .3 0 .4


Late

ral

flapp

ing

angl

e, β

1s (

deg.

)

µ

(d) Lateral flapping angle

Fig. 6 Bladeflapandlaghingerotationanglefor UH-60A at�I� �b�� #a"

13

-1.2 105

-8 104

-4 104

0

4 104

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Sha

ft p

itch

mom

ent

(in-

lb)

µ

(a) Shaftpitch moment

-1.2 105

-8 104

-4 104

0

4 104

0 0.1 0 .2 0 .3 0 .4

FLT 85

CAMRAD II

Sha

ft r

oll

mom

ent

(in-

lb)

µ

(b) Shaftroll moment

Fig. 7 Main rotorshaftmomentfor UH-60A at� � �F�6� �!� #!"

- 4

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4


Long

itudi

nal

TP

P t

ilt a

ngle

(de

g.)

µ

(a) Longitudinal tilt angle

- 4

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4


Late

ral

TP

P t

ilt a

ngle

(de

g.)

µ

(b) Lateral tilt angle

Fig. 8 TPPtilt anglein aninertial coordinatesystemfor UH-60A at�c� �b�� !#!"

14

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (Sideslip = 0 deg.)Sideslip = 5 deg. trimSideslip = -5 deg. trim

CP TR

µ

(a) Tail rotor power

- 4

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)Baseline (Sideslip = 0 deg.)Sideslip = 5 deg. trimSideslip = -5 deg. trim

Late

ral

TP

P t

ilt a

ngle

(de

g.)

µ

(b) Lateral TPPtil t angle

- 8

- 4

0

4

8

1 2

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (Sideslip = 0 deg.)Sideslip = 5 deg. trimSideslip = -5 deg. trim

Rol

l at

titud

e (d

eg.)

µ

(c) Roll attitude

- 2

0

2

4

6

8

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)Baseline (Sideslip = 0 deg.)Sideslip = 5 deg. trimSideslip = -5 deg. trim

Late

ral

flapp

ing

angl

e, β

1s (

deg.

)

µ

(d) Lateral flapping angle

Fig. 9 Effectsof sideslipanglefor UH-60A at�d� �b�� !#!"

15

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (with interference)Without interference

CP MR

µ

(a) Main rotor power

0

0.001

0.002

0.003

0.004

0.005

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (with interference)Without interference

CP TR

µ

(b) Tail rotor power

- 8

- 4

0

4

8

1 2

0 0.1 0 .2 0 .3 0 .4

FLT 85

Baseline (with interference)

Without interference

Pitc

h a

ttitu

de

(d

eg

.)

µ

(c) Pitchattitude

- 2

0

2

4

6

8

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)

FLT 85 (Blade 2)

Baseline (with interference)

Without interference

Long

itudi

nal

flapp

ing

angl

e, β

1c (

deg.

)

µ

(d) Longitudinal flappingangle

Fig. 10 Effectof interferencefor UH-60A at� � �F�� !#!"

16

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (35.14 ft^2)38.654 ft^2 (10% higher)31.626 ft^2 (10% lower)

CP

µ

(a) Total power

- 4

0

4

8

1 2

1 6

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)Baseline (35.14 ft^2)38.654 ft^2 (10% higher)31.626 ft^2 (10% lower)

Long

itudi

nal

TP

P t

ilt a

ngle

(de

g.)

µ

(b) Longitudinal TPPtilt angle

- 8

- 4

0

4

8

1 2

0 0.1 0 .2 0 .3 0 .4

FLT 85Baseline (35.14 ft^2)38.654 ft^2 (10% higher)31.626 ft^2 (10% lower)

Pitc

h a

ttitu

de

(d

eg

.)

µ

(c) Pitchattitude

- 2

0

2

4

6

8

0 0.1 0 .2 0 .3 0 .4

FLT 85 (Blade 1)FLT 85 (Blade 2)Baseline (35.14 ft^2)38.654 ft^2 (10% higher)31.626 ft^2 (10% lower)

Long

itudi

nal

flapp

ing

angl

e, β

1c (

deg.

)

µ

(d) Longitudinal flappingangle

Fig. 11 Effectof fuselageflat plateareafor UH-60A at�c� �F�� #a"

17

0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 596

CAMRAD II

_ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 598

CAMRAD II

_ C

P

µ

(b) L M O'Q�S QTQT[�^

0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 596

CAMRAD II

_ C

P

µ

(c) LNMPORQ�S QTQT[TV

0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 628

CAMRAD II

_ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 597

CAMRAD II

_ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 628

CAMRAD II

_ C

P

µ


Fig. 12 Calculatedandmeasuredpowercoefficient for STD/UH-60L

18

0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 561

CAMRAD II

~ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 603

CAMRAD II

~ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 561

CAMRAD II

~ C

P

µ

(c) LNMPORQ�S QTQT[TV

0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 567

CAMRAD II

~ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 567

CAMRAD II

~ C

P

µ


0

0.2

0 .4

0 .6

0 .8

1

0 0.1 0 .2 0 .3 0 .4

FLT 556

CAMRAD II

~ C

P

µ


Fig. 13 Calculatedandmeasuredpowercoefficient for WCB/UH-60L

19

- 5

0

5

1 0

1 5

2 0

2 5

3 0

0 0.2 0 .4 0 .6 0 .8 1

r/R = 0.5

r/R = 0.7

r/R = 0.9

α

M

(a) STD/UH-60L

- 5

0

5

1 0

1 5

2 0

2 5

3 0

0 0.2 0 .4 0 .6 0 .8 1

r/R = 0.5

r/R = 0.7

r/R = 0.9

α

M

(b) STD/UH-60Lwith WCB airfoils

- 5

0

5

1 0

1 5

2 0

2 5

3 0

0 0.2 0 .4 0 .6 0 .8 1

r/R = 0.5

r/R = 0.7

r/R = 0.9

α

M

(c) WCB/UH-60L

Fig. 14 Angleof attackversusMachnumberat� �

= 0.011 and � = 0.24

20

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 1.015r = 0.995RMS = 2.0225E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.993r = 0.995RMS = 2.8172E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 1.060r = 0.994RMS = 2.2579E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 1.052r = 0.970RMS = 4.0415E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 1.027r = 0.992RMS = 4.6508E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.832r = 0.867RMS = 3.0164E-5


Fig. 15 Calculatedandmeasuredpowercoefficient for UH-60A (AirloadsProgram), �eD �H�!�

21

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.436r = 0.944RMS = 6.2228E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.344r = 0.916RMS = 8.1571E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.907r = 0.844RMS = 7.1231E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.432r = 0.956RMS = 15.240E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

m = 0.459r = 0.593RMS = 6.1474E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP CALC

CP MEAS

Not enough data


Fig. 16 Calculatedandmeasuredpowercoefficient for UH-60A (AirloadsProgram), �e7 �H�!�

22

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 1.042r = 0.997RMS = 1.4217E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 0.987r = 0.997RMS = 1.2302E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 1.045r = 0.995RMS = 2.9285E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 1.030r = 0.975RMS = 3.4586E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 1.018r = 0.990RMS = 1.9127E-5


0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

CP MR CALC

CP MR MEAS

m = 0.821r = 0.908RMS = 4.3542E-5


Fig. 17 Calculatedandmeasuredmainrotor powercoefficient for UH-60A (Airloads Program), �8D �H�!�

23

0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 1.093r = 0.994RMS = 0.021069


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 1.003r = 0.988RMS = 0.017743


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 1.034r = 0.991RMS = 0.015666

(c) L M ORQ�S QTQT[TV

0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 1.040r = 0.999RMS = 0.057867


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 0.848r = 0.973RMS = 0.026714


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

_ C

P CALC

_ C

P MEAS

m = 0.498r = 0.984RMS = 0.053192


Fig. 18 Calculatedandmeasuredpowercoefficient for STD/UH-60L

24

0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 1.048r = 0.996RMS = 0.022893


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 0.987r = 0.993RMS = 0.017304


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 0.905r = 0.990RMS = 0.17643

(c) L M ORQ�S QTQT[TV

0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 0.875r = 0.995RMS = 0.015197


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 0.682r = 0.990RMS = 0.039625


0

0.2

0 .4

0 .6

0 .8

1

0 0.2 0 .4 0 .6 0 .8 1

~ C

P CALC

~ C

P MEAS

m = 0.583r = 0.966RMS = 0.066199


Fig. 19 Calculatedandmeasuredpowercoefficient for WCB/UH-60L

25

0.4

0 .5

0 .6

0 .7

0 .8

0 .9

1

1.1

1 .2

0.006 0.007 0.008 0.009 0.01 0.011 0.012

UH-60AUH-60A (MR)STD/UH-60LWCB/UH-60L

m

CW

(a) Slope

0.8

0.85

0.9

0.95

1

1.05

1.1

0.006 0.007 0.008 0.009 0.01 0.011 0.012


r

CW

(b) Correlationcoefficient

0

2 10-5

4 10-5

6 10-5

8 10-5

0.0001

0.00012

0.006 0.007 0.008 0.009 0.01 0.011 0.012


0

0.016

0.032

0.048

0.064

0.08

0.096

RMS

CW

RMS(UH-60A) (UH-60L)

(c) RMS error

Fig. 20 Slope,correlationcoefficient, andRMS error values

26

Performance Analysis of a Utility Helicopter with Standard ... · these UH-60ﬂight test data....

Documents

Transcript of Performance Analysis of a Utility Helicopter with Standard ... · these UH-60ﬂight test data....