Pressure fluctuations in the high-pressure common rail systems have a significant impact on the fuel injection and engine performance. In this study, the pressure fluctuation in a high-pressure common rail system was investigated using simulations. The fluctuation can be caused by hydraulic structures and control factors. The degree of influence of those two causes was evaluated and discussed in this work. First, the hydraulic and control factors that dominate the models of injection systems were established. Then, the mechanism of pressure fluctuation on high-pressure common rail systems was highlighted. A dimensionless parameter was defined to quantitatively describe the effects of control factors and hydraulic structures on pressure fluctuation. Finally, the developed model was used to study the effects of injection conditions and structural parameters on pressure fluctuation. The results show that the injection frequency has a limited effect on the system pressure fluctuation. In addition, the increase in the injection energizing time and the injection pressure will increase the hydraulic pressure fluctuations of the system, thus increasing the total pressure fluctuations of the system. Moreover, the increase in the volume by increasing the diameter was found to decrease the pressure fluctuations more effectively compared to the impact of the length, but there is a marginal diminishing effect. The results demonstrated that the effect of a 20 bar signal error and a 160 mm common rail length is almost the same on decreasing pressure fluctuations. It can be concluded that the improvements in the electronic part of the high-pressure common rail system have more potential than the mechanical part.

高压共轨系统中的压力波动对燃油喷射和发动机性能有显着影响。在这项研究中，使用模拟研究了高压共轨系统中的压力波动。波动可能是由水力结构和控制因素引起的。在这项工作中评估和讨论了这两个原因的影响程度。首先，建立了主导喷射系统模型的液压和控制因素。然后，强调了高压共轨系统压力波动的机理。定义了一个无量纲参数来定量描述控制因素和水力结构对压力波动的影响。最后，所开发的模型用于研究注入条件和结构参数对压力波动的影响。结果表明，喷射频率对系统压力波动的影响有限。此外，注射增能时间和注射压力的增加会增加系统的液压波动，从而增加系统的总压力波动。此外，与长度的影响相比，发现通过增加直径来增加体积可以更有效地减少压力波动，但存在边际递减效应。结果表明，20 bar 信号误差和 160 mm 共轨长度对降低压力波动的影响几乎相同。