Numerical Study on the Characteristics of Pressure Pulsations according to Design Factors of Fuel Rail with Self Damping Effect

자체 맥동 감쇠 효과를 갖는 연료레일의 오일 해머 및 분사 특성에 따른 압력맥동 시뮬레이션

A pulsation damper is usually mounted on the fuel rail to diminish undesirable noise in the vehicle cabin room. However, pulsation dampers are quite expensive. Therefore, several studies have focused on reducing fuel pressure pulsations by increasing the self-damping characteristics of the fuel rail. This paper is a basic study in the development of a fuel rail that can reduce pulsations via a self-damping effect. In this study, the pressure pulsation characteristics were of investigated with respect to the aspect ratio of the cross section, wall thickness, and fuel rail material through oil hammer simulations. An oil hammer simulation was performed in advance to simulate the pressure pulsations at the resonant speed, which is a time-saving way. The pressure pulsation peak of fuel rail was observed to rise as the injection period increases. Increase of the aspect ratio and decrease of the wall thickness can reduce the pressure pulsation efficiently.