Research on Flow Field Characteristics in Water Jet Nozzle and Surface Damage Caused by Target Impact

Abstract

As a new processing method, water jet processing technology has risen rapidly due to its wide range of applications, no pollution, and zero discharge. In this paper, the flow characteristics and failure characteristics of ultra-high-pressure gas-liquid jet in the range of 300 MPa are analyzed by numerical calculation. The research conclusion shows that the jet atomization diffusion is caused by the friction between the liquid medium and the surrounding gas, the mixed flow of broken water droplets and cavitation. The jet diffusion process is essentially the energy exchange process between the jet in the core area and the turbulent flow in the atomization area. The distribution of the turbulent kinetic energy in the atomization area can determine the degree of jet diffusion and the rate of energy decay. The water jet impacted the surface of the target to form a crater-like annular erosion pit. With the increase of the impact pressure, the deformation showed an overall increasing trend, and the increasing trend increased significantly. The central depression of the erosion area is caused by the damage of the material by the stagnation pressure in the core area. The flow characteristics of gas-liquid flow in the process of formation and diffusion in the high-pressure water jet nozzle are explored from the microscopic point of view, and it also provides a theoretical basis for equipment optimization in engineering.