Abstract:In the highpressure common rail injection system of highspeed diesel engines, the water pressure generated by the previous injection will have a greater impact on the accuracy of the subsequent injection. The threedimensional model of the common rail tube was established, and the computational fluid dynamics simulation software XFlow based on lattice Boltzmann method was used to simulate the pressure fluctuation in the common rail tube. The influence of the key parameters of the Helmholtz filter on the wave suppression effect was summarized. With the increase of the volume of the filter cavity, the length and diameter of the small hole, the fluctuation amplitude firstly decreases and then increases. There are optimal filtering sizes, which are 6.283 mL, 2 mm and 3 mm respectively. The filter has the best size combination, and the reason for this trend was analyzed according to the electrohydraulic similarity theory. Finally, the filtering effect of the 1.5, 2.5, and 3.5 ms injection pulse width was verified under the optimal filter size combination. The filter attenuation rate can reach 60.3%, 76.2%, and 63.8%, respectively. There is a good filtering effect in the fuel injection pulse width.