Effects of design parameters on cavitation in a solenoid valve for an electric vehicle braking system and design optimization

Abstract

Keeping pace with the current rapid development of clean energy, hybrid cars and electric vehicles are receiving extensive attention. Inelectronic control brake systems, which are essential to these vehicles, a solenoid valve is used to control the hydraulic pressure, whichboosts the driver’s braking force. However, strong cavitation occurs at the narrow gap between the ball and seat of a solenoid valve dueto sudden decreases in pressure, leading to severe damage to the valve. In this study, we numerically investigate cavitation in a solenoidvalve to discover geometric parameters that affect cavitation, and we develop an optimal design to minimize the cavitation using an optimizationtechnique. As a result, we propose two design guides for the solenoid valve subject to cavitation: the ratio of the narrowest gaparea to the inlet area and the narrow gap length. We also find that preventing a sudden reduction of a flow passage is important to reducingcavitation. Finally, using an evolutionary algorithm for optimization we minimize cavitation. The optimal design results in a maximumvapor volume fraction of 0.051, compared to 0.74 for the reference model.