Particles impact characteristics on cutting surface during the abrasive water jet machining: Numerical study

The cutting performance of an abrasive water jet mainly depends on the abrasive particle's velocities and impact angles as well as the physical properties of the particles and the workpiece being cut. This ultimately causes the different modes of erosion process at the time of cutting of the job specimen. During the cutting process the cutting profile changes with the depth of the cut to form the kerf. Due to the change of radius of curvature of the cutting surface with depth, the erosion process per unit depth decreases because of the changing of the impact angle. Here comprehensive numerical studies have been carried out to find the particle impact characteristics on the groove wall (cutting surface) as well as side walls for different radii of curvature. The results obtained from the simulations have indicated that the particle impact angles depend on the radius of curvature. The study has shown that the particles have a tendency to slide or stay close to the cutting surface for the large radius of curvature and have very small impact angles. The particles' primary impact velocity are decreased little, however, the particle's impact velocities are significantly decreased for the secondary, tertiary and following impacts due to fluid drag. The numerical simulation results have been used to calculate the particle's distribution factor for both deformation wear and cutting wear. The distribution factors indicate that the particles have tendency to slide on the groove wall for higher radius of curvature. These findings are consistent with the literature.