Boundary conditon about interior

zhou

Hi,Everyone. My case is to solve an electrolyte flow in a channel and the wall of channnel is porous media. I solve the electric potential as UDS and i needs to consider the species diffusion in porous media. Thus,I need to consider two regions: one is region in channel , another is region in porous media. Also i set "interior" as boundary condition between porous media and channel. However, there is no information needed to input at boundary condition panel in FLUENT. Actually, the gradient of UDS should be continous at this "interior" boundary between porous media and channel. My question: If i don't set this boundary condition because there is no input requirement in boundary condition panel, I wonder if FLUENT will set it as default and deal with the gradient of UDS as continuous in this "interior" boundary.If not, how FLUENT deal with this kind of "interior" boundary condition. Fluent will consider that the scalar or species at "interior" is like continous or something else. How should i define my "interior" boundary condition? Thanks.