The heat–fluid–solid coupling mechanism of the optimal jet angle for high-pressure water jet erosion of aluminum

A heat–fluid–solid coupling method was established to calculate the flow and stress fields, and the changes in temperature pressure fields and erosion stresses on aluminum surfaces under 100 MPa submerged water jets were studied. The results show that the impact temperature is the key factor affecting the aluminum erosion area and jet angle under viscous dissipation. The water jet can produce an impact temperature of 80 °C, and the area above 70 °C is more than ten times that of pressure above 80 MPa. The maximum tensile and shear stress under the temperature–pressure coupling field are 1.5 times and 6 times that under the pressure field, respectively. Under the pressure field, aluminum will not be destroyed, while under the temperature-pressure coupling field, aluminum will produce tensile and shear failure, and the damage radius is 4–6 times the nozzle diameter. With the jet angle increase, the impact pressure decreases, and there is no optimal non-zero jet angle for erosion stress under the pressure field. With the jet angle increase, the impact temperature increases, the 70 °C isotherm and 80 MPa isobar move close to each other, and the coupling effect of the temperature and pressure fields against erosion stress increases, and there is an optimal jet erosion angle. The optimal jet angle of maximum tensile and maximum shear stress varies from 35° to 0° and from 25° to 0°, respectively. The optimal jet angle of maximum tensile stress and shear failure area decreases with the increase in spray distance.