Automatic Wall Function
 

Under the section of "Automatic Near-Wall Treatment for k-omega Based Models" on page 91 of CFX 5.7 user manual, a1 is used in the equation for ustar. What is that constant? I can't find it anywhere in the user manual. Is it the same as alpha1 = 5/9?

Thanks for the help.

Craig

I know this is a very old thread but I have the same problem and want to know what a1 in the equation of u_star should be?
Is it the same constant as used in the SST-Model? a1=0,31?

Thank you for your help.