trouble: F(y) function in external layer of Baldwin-Lomax model
 

Hello!
I'm trying to verify my code with Baldwin-Lomax turbulence model for the most simple problem: flat plate boundary layer.
I set Reihardt turbulent boundary layer profile as initial condition for velocity and calculate once (before time steps) turbulent viscosity. Surprisingly, I get very low values according to external layer formula. Indeed, it is only 1.7 of molecular viscosity even at y=0.
I suspect that the reason is F(y) function, which is used to obtain F_max and y_max. It reaches its maximum too early and then is close to constant, so, probably, the value of y_max is wrong. I have repeated this in Maple and got the same result, so the reason is some misunderstanding, not the bugs in code. Has anyone calculated F(y) for a flat plate? What shape must it have?