[mabe20]

Hi all, I am currently trying to validate the Cl and Cd for a NACA 0020 airfoil, modeled in 3D.

My problem is that at an angle of attack of 2 degrees, the lift and drag forces are coming double of what they should be, as per the experimental data I have. When tested on angles of 0 4 6 8 and 10 degrees, the produced values are all within 5 % of the experimental data. At 12 degrees, the values are very high again.

I am using duplicates on the fluent setup so nothing should be changing, does anyone have any idea as to the issue.

Y+ values at airfoil surface are between 0.5 and 1.5 so these are also good.

I am using a structured mesh through ICEM and using k-e realizable with enhanced wall treatment. The mesh is decent quality except for about 0.001 % which are showing high skewness, but are located in irrelevant locations far from the airfoil, and are in no way effecting convergence (solution converges after around 60 iterations)

Note: tried using k-w SST also, but still got the same as the k-e model.

Don't know if anyone has experienced the same problem.

Thanks for any help

Mik