[Qinger]

Hello everyone, I have some problems with Ansys, hope someone can help me to deal with it.
My structure consists of three parts: water Zone at the top of the structure, full of water; poros Zone in the middle ;solution Zone at the bottom with inlet and outlet, at the inlet the mixture from water+substance A(Soluble material) with steady velocity flow into the solution Zone. I want to see the Diffusion process in the water zone of substance A from solution zone through the poros Zone.
1)
should species Transport model be used ,so that i can give the diffusionscoefficient ? but all fluid/poros Zone will be the material i specified in the species model, so how i let the water Zone just fulfilled with water?
2)
how to set the System coupling between the poros Zone with the 2 others Zone, porous jump or wall ?
I spent a long time to solve these two problems, till now i can't figure it out.
If anyone has the some ideas, please help me.

Kind of regards.
Qinger