Numerical Research on Multi-Particle Movements and Nozzle Wear Involved in Abrasive Waterjet Machining

Multi-particle velocities and trajectories in abrasive waterjet machining are of great value to understand the particle erosion mechanism involved in the cutting process. In this paper, the whole-stage simulation model is established from the high-pressure water and abrasive particles entering the nozzle to the mixed abrasive jet impacting the workpiece based on the SPH-DEM-FEM method. Comparing the simulation results with the experimental results under different process parameters, the capability of the proposed model is systematically validated. The model is applied to study the mixing and accelerating process of abrasive particles, and the results show that a speed difference is existed between the water and abrasive particles after being ejected from the nozzle. In addition, the nozzle wear pattern is also analyzed carefully. It is discovered that the most serious wear happened at the junction of the mixing chamber and the focusing tube. And the focusing tube wear is uneven and spreads downward.