Coupling Radiation with Flow model
 

Hello everyone,
I'm trying to model the radiation on vegetation. I have both an air zone and vegetation zone in my domain. In the radiation model, the surface of my vegetation zone has to be set as "wall'. But in m flow model,I do not want to have a "wall' boundary condition on the surface of the vegetation, because the flow is supposed go through the vegetation in my case.
I'm wondering if there is a way that allows me to model the surface of vegetation zone so that the flow can go through it and also participate in the radiation model.
I don't know if I made my point clear. Please let me know if you have question. I appreciate your help.