【Turbulent models and Near wall function】

lenovosk3

I'm always puzzled about how to set the first layer of the mesh. Although I know it's important to the CFD prediction.
Today I consulted it with my peer (thank him a lot). After discussion with him, I rechecked the help document of CFX and Fluent. And I got some guidelines to generate a fine mesh.
CFX and Fluent does not treat the near wall function same. CFX uses a scalarble function to calculate the near wall boundary. This option could handle a large span of you first Yplus, and it could select the most appropriate model to your wall. And Fluent use the real near wall function. This is a serious restriction to your first grid Yplus.
Also one could calculate the first grid spaceing on your paper. Once you got Re and the reference length and the first grid Yplus you want. You could get your first grid spaceing.

LOGO213

seems good ,tks