차량 브레이크 밸브 시스템에서 공동현상을 최소화하기 위한 수치해석 및 최적설계

Abstract

In electronic control brake system which is essential to hybrid cars of electric vehicles, a solenoid valve is used to control hydraulic pressure of an oil flow that boosts driver’s braking force. However, due to a narrow flow gap between the ball and seat of the valve the flow velocity is extremely high leading to severe cavitation and consequent damage on the valve. Here, we numerically investigate the effects of valve geometrical parameters on the cavitation and suggest an optimal valve design to minimize the cavitation. Numerical results show that critical parameters affecting cavitation include contact diameter, gap length, and area ratio of minimum gap to inlet and cavitation number can be used to evaluate cavitation strength. In addition, the optimum valve design obtained by using an optimization technique shows 94 % reduction in cavitation in terms of maximum vapor volume fraction as compared to a reference valve model.