UDF Help
 

Hi,

I'm modelling species transport with fluid flow in intersecting cylinders, with a constant concentration at the inlet. My question concerns the treatment of the wall concentration. Fluent will only allow a either a zero flux or a specified value of wall concentration. However, a more realistic treatment at the wall involves specifying a solute flux entering the wall in terms of fluid side solute concentration and a wall permeability function.

The flux equation is of the form:

q = -D*(delta C / delta n) @ the wall

= k*Cw, where Cw is the wall concentration and k is a constant wall permeability

Do I need a UDF to model this flux? If so, I would really appreciate a few pointers on how to go about this. I am aware of a HEAT_FLUX UDF. Can this be used to model species transport?

Any help or advice would be greatly appreciated,

All the best,

Paul