Effect of nozzle pressure ratios on the flow and distribution of abrasive particles in abrasive air jet machining

Effect of nozzle pressure ratio (NPR) on the flow and distribution of abrasive particles was investigated to improve supersonic abrasive air jet machining (AAJM) effect. The supersonic air-particle flow was simulated via CFD-DEM modeling, which was verified by AAJM experiments. It was concluded that NPR determined the acceleration and distribution of particle flow by controlling the structure and turbulent kinetic energy of the air jet free-flow field. When NPR = 1.12, the particle flow field had a longer stable region and a higher particle velocity, and the radial distribution resembled an n-shape. Further, in AAJM experiments, when the material was fixed in the stable region of particle flow field, the impact stresses were relatively high and uniformly distributed. Thus, when NPR = 1.12, the target material is fixed in the stable region of the abrasive particle flow, and the target material can obtain a better machining effect in the AAJM. • The motion characteristics of abrasive particle flow was simulated via CFD-DEM modeling. • The effect of nozzle pressure ratio on abrasive particle flow field was analyzed. • The stress distribution on workpiece surface in abrasive jet machining was measured quantitatively. • The optimum parameters of abrasive jet generation system were obtained.