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2D Airfoil modeling using Spalart Allmaras Model |
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#1 |
New Member
Mahbub Islam
Join Date: Mar 2010
Location: Bangladesh
Posts: 24
Rep Power: 16 ![]() |
I am trying to find lift and drag coefficient of NACA2412 airfoil using Spalart Allmaras (S-A) Model for Reynolds number 10^6. But the solution is not converging and calculated Cd and Cl values are far from actual one. I have checked y+ value in between 1~28.
Can anyone suggest me about improving convergence criteria for S-A model? or Any reading material related to using S-A model in fluent? Is there any special tricks on meshing? or How I can modify mesh in fluent to improve convergence? Thank you in advance. Waiting for reply. |
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#2 |
Senior Member
Join Date: Nov 2009
Posts: 411
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y+ from 1 to 28 means your grid is bad. For Spalart Allmaras you need to keep your y+ less then 1 OR larger then 100. Using a grid with y+ from 1 to 100 will give you a bad solution.
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#3 |
New Member
Mahbub Islam
Join Date: Mar 2010
Location: Bangladesh
Posts: 24
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Thank you DoHander.
Can you suggest me any procedure by which I can reduce y+ closer to 1. I will be highly grateful for this help. |
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#4 |
Senior Member
Join Date: Nov 2009
Posts: 411
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You can estimate the height of the first row of cells at the wall imposing an y+ of say 100 and providing the Mach and Reynolds numbers for your case. You have an y+ calculator here in cfd-online from which you can estimate what is the minimum cell height at the wall.
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#5 |
New Member
Mahbub Islam
Join Date: Mar 2010
Location: Bangladesh
Posts: 24
Rep Power: 16 ![]() |
Thank you DoHander. I have tried with the calculator to calculate the cell height. Not yet successful.
Probably I have to take more care about mesh formation. If you have any 2D airfoil mesh you may share with me. That will be a great help. |
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#6 |
New Member
Mahbub Islam
Join Date: Mar 2010
Location: Bangladesh
Posts: 24
Rep Power: 16 ![]() |
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Tags |
naca2412, spalart allmaras, turbulence, turbulence model |
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