Numerical study on collision characteristics for non-spherical particles in venturi powder ejector

•CFD-DEM coupling approach was used to discuss the movement and collision characteristics of particles.•DEM-FEM coupling approach was used to discuss the stress change of walls due to impact.•The collision characteristics of non-spherical particles were focused on in the numerical study.•Except the difference of shape, the volumes, superficial areas and material of particles are approximately the same.

The venturi ejector forms vacuum causing by venturi effect which makes particles enter into ejector. The conveying process of two kinds of non-spherical particles in the venturi powder ejector was respectively simulated with using CFD-DEM coupling approach, and the collision characteristics among particles were analyzed. The influence of the particle impact on the wall stress was analyzed, and the changed reason of the wall stress from collision behaviors among particles was deeply discussed with using DEM-FEM coupling approach. The present analyses show that hot spots of particle-wall collision occur around the ejector nozzle, both the particle-particle and particle-wall collision frequencies for the cylinder-shaped particles are larger than those for the tablet-shaped particles, and the force strength by collisions for the cylinder-shaped particles is larger than that for the tablet-shaped particles.