Pressure instability in two-phase porous media simulation

[Muhyminul Islam]

Hlw everyone,

I am  currently working on a two-phase flow problem in a porous medium, where one phase invades the other. During the invasion, when the advancing phase coalesces, I observe  pressure instabilities.To troubleshoot this, I have tried reducing the time step and increasing the maximum refinement level (up to RL = 10), but neither approach has resolved the issue. I have attached my source code and an animation of the simulation results.

I would be very grateful for any suggestions or guidance on how to stabilize the pressure field in this case, or any advice on what I might be doing wrong.Thank you in advance for your help.

Best regards

Muhymin