Also, for my previous question of incomplete flow.nI ran the steady simulation with 100000 number of DPM steps. I tried to visualize physically what going on inside the region where the particle disappear . For that I did the steady tracing with velocity contour and velocity vector on the plane . The pictures from the results are below. Can somebody tell me what going wrong on the region? why they all are getting trapped in a very short distance after coming out from the nozzle and not reaching to the outlet? nI set the Boundary condition - (trap) on the wall of big cylinder and set the angular rotation of 4 rpm. n