Binary particles have abnormal behavior

When I simulate binary particles, using kn=1000 there is unusual movement of the particles. When I increase kn to 9000, the particles are blown out. When I decrease kn=10, the abnormal behavior of the particles decreases, but there are still some particles that fluctuate constantly. How do I adjust to make the particles move normally. (I have adjusted neighbor_search_n to 1. And when I use hertzian model with Young’s modulus set to 5e8, the simulation time becomes very long)

I am not able to reproduce (I tried serial and dmp runs). Please try with the latest version (24.1.1) and if you still have the same issue, provide more details about your system (OS, Compiler, serial, dmp or smp runs).

I have discovered the problem. I found that when I set dp0 to 0.001, the above problem occurs. What does dp0 affect if there is only one solid phase, but with different particle sizes.

Hello Jeff. I looked at the code and when I used the particle_input.dat to input the particles, I didn’t see that dp0 in MFIX affected the motion of the particles. I’d also like to ask you why dp0 causes anomalous motion of particles.