Hi,

I have two questions about the wall function formulation in the k-eps model.

- In what point of the cell the y+ is calculated? It is the cell centroid or the face oposite to the wall?

- The wall function is used to calculate the velocity only on the first row of cells next to the wall or until the end of the boundary layer?

Any help will be apreciated!

Galeazzo

It's calculated in the cell centroid (there is no opposite face on a tet mesh) and it's only used in the first cells that are adjacent to the wall.

Jason

Thanks Jason!

please help me to find the answer of following questions. 1. what is the theoretical farmula of Y+? 2.what is wall function's farmula and if there are other function to calculate the turbulent properties then please tell me?. 3.As per guide line to increase Y+ values we should make coarse grid near to flow surface but if we want to capture boundary layer effect too then how to choose optimum mesh size,so we can satisfy both requirement?. It will be very kind of you,if u send aswer of my questions on my e-mail id navneet@isac.ernet.in thanks with regards navneet