Abstract:In order to improve the breakup condition of oil beams and increase their initial turbulent kinetic energy at the exit of the nozzle, the high injection pressure of 180MPa was used. The changing relationship between the physical properties of the non-normal fuel and the pressure under the influence of the high pressure injection was derived. The spraying flash photography test bench based on the high pressure constant vessel was set up. The three-dimensional CFD model of nozzle inner flow field was established on software AVL FIRE. The simulation model was modified according to the spraying test results. The three-dimensional flow state and cavitation flow characteristics of nozzle inner gas-liquid two-phase flow field were analyzed. The results show that when the temperature is constant, the density, the speed of sound and the bulk modulus of fuel increase with the ascent of pressure, the change of these physical parameters of non normal fuel is beneficial to the production of cavitation gas and enhance the cavitation effect; increasing the fuel injection back pressure restrains the flow of cavitation gas and fuel, so the cavitation effect is weakened; with the increase of nozzle diameter, the high speed region of fuel becomes more extensive and the cavitation effect becomes more prominent. The increase of the injection angle also helps to enhance the cavitation effect, but the effect is not obvious due to the limitation of the structure form. So the reasonable matching relationship between the nozzle diameter and injection angle is helpful to improve the initial turbulent kinetic energy intensity at the outlet of the nozzle, and obtain a better jet state.