UDF for wall shear stress
 

Hi everybody! I'm trying to simulate a laminar flow of a Bingham Fluid or Herschel- Bulkley Fluid respectively. I think I have to write an UDF for the calculation of the wall shear stress, as the equation in Fluent for the wall shear stress is only valid for newtonian Fluids. Is there anybody who knows how to write such UDF? I could not find the variables and arguments Fluent uses. Thanks a lot Basti