Numerical simulation study on optimization of ultra-high pressure post mixed abrasive water jet nozzle

In order to improve the efficiency of abrasive water jet system for cutting hard and thick roof, the influence of nozzle structure parameters on the velocity and distribution of abrasive particles was studied by using numerical simulation software. The results show that the outlet velocity of abrasive increases with the increase of water nozzle diameter, and the abrasive particles are mainly concentrated in the outer boundary area of water jet on the exit section; when the inlet angle and position of the abrasive are 60° and 3 mm, respectively, the velocity of the abrasive particles is the maximum, and the axial regional concentration is the best. Based on the above rules, orthogonal experiment and variance analysis are carried out on the influencing factors, and the optimal parameters are obtained as the diameter of water nozzle is 1 mm, the position of abrasive inlet is 0 mm, and the angle is 60°. Through the slit experiment comparison, it is found that the slit width is decreased by 12.0% and the depth is increased by 26.5% after nozzle optimization.