Hi to all.

Could u please give me an approximation to calculate y, for a given yplus, in a turbulent channel flow?

Thanks in advance Best regards Hadi

An easy formula is

y=14*y+*(viscosty/(density*velocity))

This is actually for a flat plate, but gives a fairly good start when building your extrusion surface for pipe flow.

Tom

Thanks Tom, for the answer, but which velocity do i have to use?

Hadi