Discussion Forum

Hi,

I am trying to model unsaturated flow in soil with the presence of macropore. The model consists of two main domains (i.e., matrix at left and macropore at right). For simulating film flow in macropore, I have used two phase laminar flow (air-water), phase field approach and assigning an water inlet with mass flow at top of that domain. For the flow in matrix domain, I used Richards equation physics with assigning a water-transfer interface between macropore and matrix (i.e., with a mass flux interface dependent on the pressure difference between the domains). The outcome I am expecting here is film flow along the inner macropore surface with water transfer from adjacent macropore boundary to matrix or vice versa.

I understand that this model is computationally very expensive, but that is not the issue for me as I am gonna run it in a cloud-computing environment. The problem is this model is either not converging or the initial values are not consistent. I have tried using a fully-coupled solution approach as well as segregated approach for the time-dependent solver, but still solution not converging.

I would urge the respective peer group and experts to look at my attached model. It is completely okay if you modify the existing model in any form for better conceptualization of the problem or for betterment of running without any error. This is surely an interesting problem to solve for the preferential flow and transport study community. Thank you.