Alessandro CORSINI, Giovanni DELIBRA · comes from biomimesis • Biomimesis is the examination of...
Transcript of Alessandro CORSINI, Giovanni DELIBRA · comes from biomimesis • Biomimesis is the examination of...
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Alessandro CORSINI, Giovanni DELIBRA
Industrial fan design and investigation by means of URANS and LES based numerical methods
FMGroup @ DIMA-SUR
www.dima.uniroma1.it
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
WHO’S WHO @ FluidMachinery Group, DIMA-SUR
Previous CFD team members (… now in industry)Carlo IossaFilippo MenichiniStefano MinottiAndrea Santoriello
CFD software
FEM f90 & C++ XeniosFVM f90 T-FlowsFVM OpenFOAM
Marco BassettiDomenico BorelloLucio CardilloAlessandro CorsiniGiovanni DelibraAndrea Marchegiani
Franco RispoliGiuseppe RiccucciRafael Saavedra @ UDEP Piura, PeruFabrizio SciulliEsmeralda TuccimeiPaolo Venturini
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
WHAT ARE WE DOING w.r.t. CFD
URANS, LES and hybrid LES/RANS for heat and mass transfer & combustion
Particle Tracking, Fouling and Deposition
development and assessment of new models & numerical technologies
computations of industrial flows, mainly for turbomachinery applications
Partner Industries
Faggiolati PumpsFlaktWoods GroupFieni Srl
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Industrial flows computed with OpenFOAM• Axial flow fans:
• control of separation• operations under strong pressure fluctuations
New projects• Large centrifugal fans: rotor-stator interaction• LES of onshore caisson for Wells Turbine with Actuator Line Methodology
Most of these projects were run on CINECA or CASPUR[*] HPC grids
[*]CASPUR is now part of CINECA
Outline
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Up‐front logic for CFD oriented design,where is to be located?
at conceptual stage to provide hints of the basic governing flow physics
e.g. biomimesis
at preliminary stage to explore possbile flow configuration to exploit the selected physical mechanisms
at the detailed design stage to elaborate the range of virtual proto‐typescost reduction in the R&D process
less “real” proto‐types and test‐rigs
larger set of explored design solutions available since the early stage of the process
design solution oriented by a deeper knowledge of the underlying flow physics
not just empiricism
from D. Jakipse, 2001
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
AXIAL FLOW FAN FOR TUNNEL AND METRO UNITSwith
FlaktWoods Group
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Industrial fans for tunnels in metropolitan mass-transfer systems:
•need to comply with new EU legal requirements that pose strict efficiency andacoustic emission limits;
•need to be able to adapt to complex operating conditions such as:
• smoke and hot (400°C) gas extraction in case of fire
• the destabilising effects of compression and expansion pressure waves generated by the passage of the trains inside the tunnels
•need to increase pressure rise and blade loading because of market request
Problem to solve
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Industrial fans for tunnels in metropolitan mass-transfer systems:
•need to comply with new EU legal requirements that pose strict efficiency andacoustic emission limits;
•need to be able to adapt to complex operating conditions such as:
• smoke and hot (400°C) gas extraction in case of fire
• the destabilising effects of compression and expansion pressure waves generated by the passage of the trains inside the tunnels
•need to increase pressure rise and blade loading because of market request
Problem to solve
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Industrial fans for tunnels in metropolitan mass-transfer systems:
•need to comply with new EU legal requirements that pose strict efficiency andacoustic emission limits;
•need to be able to adapt to complex operating conditions such as:
• smoke and hot (400°C) gas extraction in case of fire
• the destabilising effects of compression and expansion pressure waves generated by the passage of the trains inside the tunnels
•need to increase pressure rise and blade loading because of market request• stall control is a key technology for axial fan operations
Problem to solve
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
• need to increase pressure rise and blade loading because of market request• stall control is a key technology for axial fan operations• one of the possible source of inspiration for new stall resistant solutions
comes from biomimesis
• Biomimesis is the examination of nature, its models, systems, processes, andelements to emulate or take inspiration from in order to solve human problems.
• Possible solution to design stall resistant fan blades: exploiting the peculiar shapeof the leading edge of the flippers of the humpback whale
Problem to solve: possible ways to solve it
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
exploiting the shape of the leading edge of the flippers of the humpback whale
How flipper tubercles make a mercyless hunter
main objective of the work was to scrutinise the performance of a sinusoidal leadingedge on a cambered airfoil (NACA4415); comparison with symmetric profile(NACA0015) was provided
influence of the leading edge geometry at different operating conditions was studied
assessment of a modified sinusoidal-shaped leading edge in terms of lift and dragperformance
Corsini, A., Delibra, G., Sheard, A.G., “On the role of leading-edge bumps in the control of stall on-set in axial fan blades”, Proceedings of the FAN 2012 Conference, Senlis, France, 2012.
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
lift coefficient shows that the introduction of a sinusoidal-shaped leadingedge modifies the aerofoil performance during stall:
• early recovering in the aerodynamic work capability• 30% gain in lift after stall for the WHALE4415 cambered airfoil
How flipper tubercles make a mercyless hunter
Lift coefficient vs Angle of Attack
Corsini, A., Delibra, G., Sheard, A.G., “On the role of leading-edge bumps in the control of stall on-set in axial fan blades”, Proceedings of the FAN 2012 Conference, Senlis, France, 2012.
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
the leading edge geometry directly impacted on the aerofoil velocity andvorticity fields:
• leading edge sinusoid peak > stabilising effect at the trailing edge• leading edge sinusoid through > separation
How flipper tubercles make a mercyless hunter
separation
Pressure isolines on the suction surfaceNACA4415
Corsini, A., Delibra, G., Sheard, A.G., “On the role of leading-edge bumps in the control of stall on-set in axial fan blades”, Proceedings of the FAN 2012 Conference, Senlis, France, 2012.
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
JFM 224Blade section ARA-D
Diameter at the tip 2240 mmBlade count 16
Hub-to-tip ratio 0.5hub tip
Chord (mm) 143 92.5Solidity (-) 0.64 0.21
Pitch angle (deg) 48 24Volume Flow Rate 150 m3/s
Total Pressure Rise 2800 PaRotation speed 1500 rpm
Energy consumption 0.5 MW
Reynolds number, based on Dtip and Vtip exceeds 26M
A stator is present downstream the rotor but it is notaccounted for in the simulations.
Equations are always solved in the relative frame ofreference, accounting for Coriolis and centrifugal forces
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Numerical methodology
solver SRFSimpleFOAM(more or less)
approach RANSmodel non-linear (cubic) low-Re k- (Lien et al.)cell count 4.1M (2M hexa + 2.1M tetra)average y+ 1.2 (blade), 1.9 (hub & casing)domain 1 blade vane, extending 1c upstream and
2c downstream the rotornumericalschemes
CDS (momentum)QUICK (turbulent variables)
solver GAMG (pressure)CG (other eqns)tolerance: 10-10
operatingpoints
110, 130 and 150 m3/s
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
When the whale hits the fan
Design of a “whale fan” based on literature and data fromisolated airfoil
Sinusoidal profile limited to the tip of the blade
Hub was not “whaled”
• The sinusoid amplitude was chosen as 3% of the chord at tip
• The wavelength as 5% of the blade span
• 5.5 sinusoids were used, starting with a peak at the tip
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Q [m3/s] Total pressure rise [Pa]
Exp JFM224(datum)
JWFM224(whale fan)
110 2858 +1% 2831 2748 -3%
130 2752 +2% 2798 2714 -3%
150 2511 +2% 2565 2502 -2%
Validation of results
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Inner working of the bumps
Pressure isolines on the suction surface of the blade for the investigated cases
Corsini, A., Delibra, G., Sheard, A.G., “LEADING EDGE BUMPS IN VENTILATION FANS”, GT2013-94853 submitted to ASME Turbo Expo 2013, San Antonio (US)
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Inner working of the bumps
whaleFor JFM224 isolines are aligned with the leading edge ofthe blade and the only distortion comes from the tip, dueto leakage from the pressure surface.
In JWFM224 low pressure cores are generated at thetrough of the sinusoid, as already occurred with anisolated profile.
Corsini, A., Delibra, G., Sheard, A.G., “LEADING EDGE BUMPS IN VENTILATION FANS”, GT2013-94853 submitted to ASME Turbo Expo 2013, San Antonio (US)
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Inner working of the bumps
The low-pressure cores are responsible for the releasefrom the leading edge of counter-rotating turbulentstructures
The straight blade of JFM224 does not generate anylarge-scale structure apart from the tip-leakage vortex.Such vortex in J1 case interacts with a large separationzone at the tip of the blade.
Corsini, A., Delibra, G., Sheard, A.G., “LEADING EDGE BUMPS IN VENTILATION FANS”, GT2013-94853 submitted to ASME Turbo Expo 2013, San Antonio (US)
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Inner working of the bumps
In W1 the structure originates at the leading edge iscounter-rotating with respect to the leakage vortex andpartially blocks its evolution. This lead to a completereattachment of the flow on the suction surface
streamlines at 95% of the blade span
streamlines at 95% of the blade span
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Inner working of the bumpsturbulent structures, visualised with an iso-surface of the vorticity
Corsini, A., Delibra, G., Sheard, A.G., “LEADING EDGE BUMPS IN VENTILATION FANS”, GT2013-94853 submitted to ASME Turbo Expo 2013, San Antonio (US)
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Industrial fans for tunnels in metropolitan mass-transfer systems:
•need to comply with new EU legal requirements that pose strict efficiency andacoustic emission limits;
•need to be able to adapt to complex operating conditions such as:
• smoke and hot (400°C) gas extraction in case of fire
• the destabilising effects of compression and expansion pressure waves generated by the passage of the trains inside the tunnels
•need to increase pressure rise and blade loading because of market request
Problem to solve
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
solver modified version of pisoFOAM(to account for Coriolis and centrifugal effects)
approach LESmodel one equation (k) for SGS (Davidson)cell count 9M hexaaverage y+ 1.2 (blade), 1.9 (hub&casing)domain 1 blade vane, extending 1c upstream and 1c
downstream the rotornumericalschemes
CDS (momentum)QUICK (turbulent variables)
solver GAMG (pressure) and CG (other eqns)tolerance: 10-10
operatingpoint
150 m3/s
Numerical methodology
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
p ±1000 PaUbulk ±4.8%tramp 1.3x10-5 stpulse 4 ms
Inflow average velocity components
Simulation of pressure pulses
Pressure increase/drop characterisation
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
A B C
• sudden change of the pressuredistribution during the pulse (B)
• capability of the rotor to adapt toquickly the new mass flow rate(C)
• pressure isolines on the suctionsurface show a clear 90 degturning (B)
• during pressure pulse (B) isolinesare more radial and giveevidence of a stall from the hubto 2/3 of the span, while the tipsection is still capable ofcontributing to the rotor pressuredeveloping capability.
Evolution of cp for compression waveA: beginning of compressionB: middleC: end of compression tip
mid
hub
D. Borello - A. Corsini – G. Delibra – F. Rispoli – A. G. Sheard., “Numerical Investigation On The Aerodynamics Of A Tunnel Ventilation Fan During Pressure Pulses”, submitted to ETC 2013
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
tip
mid
hub
A B C
A: beginning of expansionB: middleC: end of compression
• As the pulse hits the blade (B) therotor adjust to the drop of massflow increasing the work and sothe lift over the blade
• In this case the distribution ofpressure isolines remains“vertical”, yet a strong load of thetip of the blade is recognisable
• Distributions of the pressurecoefficient show that midspan andtip sections are over-loaded
Evolution of cp for expansion wave
D. Borello - A. Corsini – G. Delibra – F. Rispoli – A. G. Sheard., “Numerical Investigation On The Aerodynamics Of A Tunnel Ventilation Fan During Pressure Pulses”, submitted to ETC 2013
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Evolution of blade loading during pressure pulsetime evolution of the integral values of forceson the blade during the increase (top) ordrop (bottom) of mass flow rate Compression wave:
as the blade stalls, the peripheral componentof force is almost null, whereas the axialcomponent shows a sudden change of sign
Expansion wave:
overall overload of the blade, as the value ofboth axial and peripheral forces doubles
D. Borello - A. Corsini – G. Delibra – F. Rispoli – A. G. Sheard., “Numerical Investigation On The Aerodynamics Of A Tunnel Ventilation Fan During Pressure Pulses”, submitted to ETC 2013
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Next
more snowmore whales
more fans (lot of fun)and something new…
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
LES of a Oscillating Water Column device coupled with Wells turbine forMediterranean operations simulated with Actuator Line Methodology (CINECA,IscraB)
Numerical tools: hasNotANameYetFoam
A glimpse of the future (i)
OWC chamber Wells turbine
Blade profile (rotor) NACA0015Dtip 500 mmDhub 375 mmSolidity 0.64Blade count 7 + 2x 3600 rpmUbulk (axial): 9.1 m/s
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Numerical computations of the performance of Technopal centrifugal fan (FlaktWoodsGroup), with particle dispersion, deposit and erosion
Numerical tools: pimpleDyMFoam (for URANS, possibly hybrid LES/RANS)pTrack (in-house FEM code for particle tracking, erosion and fouling)
A glimpse of the future (ii)
Impeller inlet diameter 1804 mmImpeller outlet diameter 3440 mmVolute outlet diameter 5600 mmImpeller blade width 400 mmVolute width 200 mmImpeller blade count 11Rotational frequency 900 rpm
Technopal fan assembly Technopal impeller rendering
FMGroup @ DIMA-SUR
Industrial fan design and investigation by means of URANS and LES based numerical methods
[email protected] - Bologna, 27 Nov. 2012
Thanks