中文摘要：

基于开源软件OpenFOAM定义两种连续的网格运动使针阀完全关闭,分三步数值模拟针阀关闭时刻喷孔内的瞬态流场。发现在某些喷油条件下压力室内有气泡形成,这与Jollet实验结果基本吻合。通过对针阀关闭后喷孔内流场的分析,阐述该气泡的形成过程。进一步分析喷孔直径、喷油压力对气泡形成的影响,结果表明当孔径增大到0.4mm时,喷孔内有气泡形成;在30~100MPa喷油压力范围内,随着喷油压力的提高,喷孔3中的气泡体积先增大后趋于稳定。

英文摘要：

The paper proposed a new algorithm of two kind of continuous mesh-moving to keep the needle closed completely on the ground of the open source software OpenFOAM,and numerically simulated the transient internal flow field during the needle closing time by three steps.Bubbles were found in the pressure chamber under some injection conditions,which was coincided with the experimental results of Jollet.Through analyzing the flow field in the nozzle after the needle was closed,this paper expounded the forming process of the bubble.Further investigation on the influence of nozzle diameter and injection pressure showed the bubble formation with the diameter expanding to 0.4mm;and the bubble volume in nozzle 3presenting an increasing tendency to stabilization with the injection pressure ranging from 30 MPa to 100 MPa.