Discussion Forum

I am simulating the diluted solute transport in a single fracture-matrix system, as described in the attached word file. The "Transport of Diluted Species in Porous Media" interface was applied, in which the "fracture" from "interior surfaces" was also used. However, I found that the calculated concentration is much lower than estimation. I respectively tested both "Transport of Diluted Species in Porous Media Interface" (without fracture) and "Transport of Diluted Species in Fractures Interface" (without porous domain) and found that all results are correct. It means that the coupling between fracture and porous matrix is not correctly designed in my Comsol simulation. I read again the user guide and noted that there was a term, called "out-of plane flux from the adjacent porous domain", in the governing eqaution for describing diluted solute transport in fracture. I suppose that this term makes my simulation results incorrect. Could anyone tell me how this built-in term is set and implemented in Comsol? Many thanks in advance.