Learning Forum

[btuck812]

I am trying to model a system where water, containing a reactant, passes through a channel which is surrounded by a hydrogel. The reactant needs to diffuse through the interface between the channel and the hydrogel, but without any fluid flow occurring within the hydrogel (convection must remain 0). On the outer surface of the hydrogel is a layer of catalyst which catalyses the reaction of the reactant decomposing into a new molecule.

So far, I have managed to model the reactant as an additional variable, which is able to pass through the interface into the hydrogel whilst keeping the flow regimes separate (by modelling the interface as a no slip wall and creating an exemption for the additional variable). However, this system doesn't allow for reactions to take place, and when modelling the water + reactant as a mixture CFX doesn't seem to have an option to segregate the flows, meaning the channel flow spills out into the hydrogel unless I make the interface a no slip wall, which prevents diffusion as well.

Is what I want to do possible? Would it be easier in Fluent? I've managed to solve this problem in other software, so I can't believe AnSYS CFX wouldn't make this possible.

Thanks in advance for any help,

Brandon

[DrAmine]

Do you need membrane like bc? I guess a picture of tge probldm is helpfull.