Experiment and simulation research on abrasive water jet nozzle wear behavior and anti-wear structural improvement

Abstract

As a non-traditional machining technology, abrasive water jet is widely used to cut almost any material without obvious heat damage and thermal stress. However, the impact of high-speed abrasive particles on the inner wall of nozzles causes serious nozzle wear. The development of nozzle wear research has been limited by the wear monitoring approaches. In this present study, a series of wear tests and numerical simulations are performed on the pre-mixed AWJ nozzles under the same conditions. The effects of cylinder length and inlet angle on wear behavior are investigated. By comparing the simulation results with the test results, it is found that the simulation method can be effectively used to study the wear characteristics, which shows that the simulation method can improve the nozzle wear research by making up for the disadvantages of the experimental research method. Finally, a new dual gradient nozzle structure is put forward, and its wear performance is analyzed by numerical simulation. The simulation results show that for the pre-mixed AWJ nozzle with inlet angle more than 30°, the new nozzle structure can reduce the erosion ratio more than 88.14%. Thus, the dual gradient nozzle structure can reduce the nozzle wear and improve nozzle life significantly without sacrificing the cutting efficiency.