cfdemSolverMultiphase

Submitted by lcy1294510602 on Tue, 11/05/2024 - 05:06

Hello everyone,

I’m currently working on a simulation using the multiphaseInterFoam solver (specifically, the PFM version cfdemSolvermultiphase from the tutorials). My goal is to model fluid injection into a porous medium with particles, but I’m encountering some issues with pressure stability. The simulation often shows negative pressures and other unstable pressure fluctuations.

I’d appreciate any suggestions or troubleshooting tips on resolving these pressure issues.

Also, since this is an unresolved method, my understanding is that the particle size should ideally be smaller than the grid cells. However, I noticed that the simulation can still run even when the particles are larger than the grid cells, which is a bit confusing to me. Could anyone clarify if this setup could be affecting my results, or if it’s normal for the solver to handle larger particles?

Thanks in advance for any insights or advice!

Forums:

isaachackett | Tue, 11/12/2024 - 10:22

@slope A number of variables, including boundary conditions, time step size, and grid resolution, can frequently result in negative pressure problems. Make sure your mesh is fine-tuned enough for your particle resolution; stability should be improved if your particle sizes are smaller than your cell sizes. The solver may still be able to roughly predict their behavior, albeit less precisely, if it permits larger particles.

lcy1294510602 | Tue, 11/12/2024 - 10:50

Thanks for your reply. This is an unresolved method, so I think the grain size should smaller than mesh size. If the particle size is larger than the mesh size, it will cause unstable. Is it correct? Besides, what does " Make sure your mesh is fine-tuned enough for your particle resolution" mean? I am quite confused. Thanks for your time and looking forward to your reply.