[spirosk]

I am trying to implement the Cebeci-Smith model in Matlab for an incompressible boundary layer. I have three questions:

1)In Van Driest's formula for mixing length i exp(y+/A+), y+ is the well-known y+ which is related to friction velocity ut, or just the distance y from the wall?

2)How can i calculate tw(stresses near the wall), maybe with Newton's experimental law?or with an empirical relation?

3)To distinguish the inner and outer region for the calculation of eddy viscosity i use an if/else with the condition of y<δ(boundary layer thickness) calculated with an empirical relation...is this valid?

Thanks in advance, i would appreciate if anyone had found and answer a paper or some text about this implementation or maybe a pipe/duct simulation of C-S.