Effect of Valve Core Speed on the Characteristics of Cavitation Flow during Fuel Pressure Relief

To obtain the influence of valve core speed on the cavitation and pressure characteristics during the pressure relief process of the high-pressure fuel, a visualization experiment was conducted to validate a three-dimensional numerical calculation model. Based on the validated model, numerical calculations were conducted to study the cavitation flow during the opening process of the solenoid valve at different valve core speeds. The results show that the cavitation in the throttling section and downstream is caused by flow separation and jet entrainment, respectively. Moreover, at the same valve lift, higher valve core speeds result in more vapor at the throttling section, and the influence of valve core speed decreases as the valve lift increases. When the valve lift is less than 0.08 mm, increasing valve core speed leads to a decrease in downstream vapor volume at the same valve lift. When the valve lift is greater than 0.08 mm, a gradually weakening periodic vortex cavitation appears above the stroke stop, and the higher the speed of the valve core, the stronger the vortex cavitation. Additionally, the pressure fluctuations at the throttling section and downstream both originate from changes in total vapor volume fraction. The pressure in the throttling section exhibits attenuated fluctuations when the valve lift is less than 0.04 mm, and both frequency components of the fluctuations increase linearly with the valve core speed. The downstream pressure fluctuations occur when the valve core stroke is less than 0.06 mm, and with increasing valve core speed, the pressure peak increases.