[Andy_bm]

Hi everyone,

There is a famous case flowfield around rod-airfoil.I made the mesh around rod and airfoil, Y+ ~ 100, U=72 m\s. I use LES model, oneEqeddy eq.
In the first case I use BC in nuSGS zeroGradient and get good results. Measurement error between calculation and experiment was 2%. But I always thought that BC zeroGradient nuSGS to give good results,when y + <~ 10.
In second case I use BC in nuSGS nutkWallFunction, nutUSpaldingWallFunction and Cd on rod became 0.3, but in experiment and in the first case Cd ~ 1.17.

How can you explain this?
What boundary conditions do you recommend in such cases?

Thanks.