Help with Free flow and Porous Media Flow (Brinkman)

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Hi all,

NOTE: I tried uploading to the forum earlier today, but once I finished writing and click "submit" it disappeared and I couldn't figure out if it was under review? or some sort of process before posting, or if it was discarded entirely. If you see a similar post by me that looks like this one, my apologies.


I am having trouble modeling using the Free flow and porous media flow (Brinkman). I am trying to model hyporheic flow by simply creating a 2D box, made of 2 layers (sediment and water). I apply velocity or pressure from the left boundary and create a lateral flow that partially seeps into the sediment bed (mimicing hyporheic flow). However, the issue I'm having is that the model will not find a solution and/or the solver won't converge unless I use very low velocities or pressure values (0.001 Pa or 0.001 m/s). I am trying to run the model using larger values of velocity, not extremely large but something around the values of 0.5-5 m/s velocity values.

I tried using another physics component, which was the free and porous media flow (Darcy), but to no avail. I tried making the cross section larger (it is 1m by 0.5 m), and again the model wont give out results unless the boundary condition is very small.

Can someone please help me figure out why the model wont let me use larger values, and how do I fix this issue? Thank you.



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