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December 31, 2012, 10:27 |
2D Airfoils at Low-Re
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#1 |
Member
Mamdouh
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 13 |
Hello everybody
Happy New Year I am working on a family of 2D Airfoils up to 10% camber and 5% thickness investigating the LSB Cl, Cd, and BL parameters for Re from 70 000 to 200 000 I've finished ICEM-meshing May anybody summarizes his experience in similar work (even by short remarks and advices) for ... 1- ICEM proper meshing criteria 2- FLUENT setting to get the best results thanks for reading any kind of help being appreciated thanks in advance GOOD LUCK for all Best Regards Mamdouh |
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December 31, 2012, 11:26 |
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#2 |
Member
Mamdouh
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 13 |
summary of my work on ICEM ...
11 to 15 times upstream 21 to 25 times downstream Geometric series 250 to 300 points in both directions on FLUENT I am trying the different suitable models and settings and I am waiting for your advices |
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December 31, 2012, 11:42 |
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#3 |
Senior Member
Join Date: Mar 2011
Location: Germany
Posts: 552
Rep Power: 20 |
Few suggestions from my side
1. Try solving this problem on Full structured quad mesh. Don't start with unstructured tri elements. 2. Resolve the boundary layer properly so that you get drag values comparable to the literature results. 3. Start with SST kw turbulence model. On 70000 Re. No the flow over the airfoil will be transitional(confirm it from the literature). For transitional flow use k-kl-w or SST transition model. 4. For SST kw ensure wall y+ = 1 and for k-kl-w and SST transition ensure wall y+ <1 and also the sufficient mesh resolution in the stream wise direction also. 5. Use Pressure Farfield boundary condition. |
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January 3, 2013, 14:08 |
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#4 |
Member
Mamdouh
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 13 |
thanks a lot dear CFD seeker for your concern and fast response,
and sorry for my delay, I faced some technical problems in my laptop I reached a mesh quality of 0.8, is that enough to consider it as a good mesh? Minimum Orthogonal Quality = 8.01112e-01 Maximum Aspect Ratio = 8.98120e+03 how can I find the value of y+ ? when FLUENT launched it force me to change the pressure far field BC ... this message appears pressure-far-field boundary conditions can only be used with ideal gases. finally, what about the constants and default values for the mentioned solution models? do you see to keep it unchanged or modify it? Best Regards and Respect Mamdouh |
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January 3, 2013, 23:51 |
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#5 | |||
Senior Member
Join Date: Mar 2011
Location: Germany
Posts: 552
Rep Power: 20 |
Quote:
Quote:
Quote:
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January 4, 2013, 11:10 |
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#6 |
Member
Mamdouh
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 13 |
thanks again and a lot
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January 4, 2013, 14:09 |
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#8 |
Member
Mamdouh
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 13 |
thank you again Dear Dr. Far
that what I already did, velocity inlet instead of pressure far field as the flow is incompressible. but the results still so bad for all models S.A, k-w, k-e, k-kl, and sst I'd like to ask about the reference zones and locations ... what is meant by it? and how can I adjust it? beside ... what model(s) you suggest for my cases? and how can I adjust the constants that embeded in it? thanks in advance Best Regards Mamdouh |
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