I am trying to define boundary conditions that cause the MPM particle to cease motion as it comes into contact with the 'leak' outlet - its a bit hard to see in that screenshot, but this one might be a bit better:nThe reason I thought 'trap' applied to MPM, and not just DPM, is that I read somewhere that as MPM is an addon module, a lot of the settings within the user interface are not tailored directly for MPM, so state DPM but can be used for both. Given that the 'trap' option appeared when I activated mpm, I assumed it would be applicable to mpm.nIf trap doesn't apply, is my only option to use the particle deposition setting to stop the particle from moving? They don't seem to work for some reason, even when minimum detachment drag force is set very high and max velocities for deposition to be very low. I have an edge sizing of 0.05mm applied to the leak outlet at particles of 2.5mm, giving 50 cells at the point of contact (over the 20-30 minimum needed for MPM to predict drag), with -0.5m/s applied as the main pipe 'outlet' BC, 100,000Pa at the pressure inlet, and 0 Pa as the leak BC. The particle remains in contact with the leak when it reaches it, but moves ever so slightly every time step, so doesn't achieve a 'rest' state.nCan you think what the issue might be? Thanks again for the help.nn