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Lift&Drag Coefficients is not accurate enough! |
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August 5, 2010, 09:41 |
Lift&Drag Coefficients is not accurate enough!
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#1 |
Member
Rasoul
Join Date: Feb 2010
Posts: 32
Rep Power: 16 |
Dear Foamers,
I'm working on a fixed/moving cylinder case. I used icoFoam solver for Re<300 and results are acceptable. When Re exceed from 300 the drag coefficients become different from literature data. I'm using pisoFoam (with LES or RAS turbulence models) solver. For example for Re=500, experimental results say that avaraged drag coefficient should be 1.18, while OpenFoam calculates it in the range of 1.35-1.5 (depending on the changing parameters like BC and initial conditions). I supposed maybe it is because of 3D effect. So I implemented the simulation for a 3D case. But still there is a considerable difference between my results and papers one. I'm wondering if one could suggest me how to fix this problem. Isn't it solver errors? To be honest I'm thinking about the accuracy of pisoFoam solver. Regards, Rasoul |
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August 5, 2010, 10:05 |
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#2 |
Super Moderator
Niklas Nordin
Join Date: Mar 2009
Location: Stockholm, Sweden
Posts: 693
Rep Power: 29 |
and grid dependency?
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August 5, 2010, 10:13 |
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#3 |
Member
Rasoul
Join Date: Feb 2010
Posts: 32
Rep Power: 16 |
Yes, of course!
My initial grid is fine and refining the mesh just increases the solution time without any considerable improve to results. I also changed the divScheme in fvScheme file. |
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