About Alpha_inf
 

In SST k-omega model, Alpha_inf was calculated by blending function and two variables, Alpha_inf,1 and Alpha_inf,2. These variables were calculated by beta_i, beta_inf and SDR also.
The question is, if the Alpha_inf was calculated by other variables, how could it be set as a constant in Fluent when it was used in SST k-omega model? Obviously, inner and outer Alpha_inf is different. How to decide the constant about Alpha_inf?
Thank you!