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NACA 0012 2D - SA model - Drag overprediction

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Old   March 27, 2019, 16:04
Default NACA 0012 2D - SA model - Drag overprediction
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Hi everyone!


As the title suggests I am facing some problems while trying to simulate the flow around a NACA 0012 airfoil. Basically, I obtain drag coefficient values which are overestimated compared against the experiments.


I am using a Spalart-Allmaras model with nu_tilda = nu and nut/nu_tilda = 3. I tried different meshes, boundary conditions and numerical scheme by I always end up with some discrepancies. E.g. for the 0 angle of attach I obtain 1e-3 instead of 6e-4



Find at this link the setup for my case:
https://we.tl/t-10bcvAXo4n



Thank you in advance for your time.
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Old   March 28, 2019, 10:40
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It may be mesh or boundary condition related.


Could you try another meshing approach other than blockMesh? I strongly recommend Construct2D for this purpose.
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Old   March 28, 2019, 12:55
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Hello.



I think You need a transitional model like k-omega SST or gamma re theta.
In Spalart-Allmaras model flow is fully turbulent everywhere so drag coefficient is overestimated.



Please correct me if I am wrong.


Best regards,
Oskar
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