喷油嘴喷孔内部空穴两相流动数值模拟分析

Numerical Simulation and Analysis of Two-Phase Flow of Inner Cavitation in Injection Nozzles

在柴油机喷油嘴喷孔内部空穴流动现象分析的基础上,建立了完全发展了的空穴流动的二维气液两相流空穴模型,并进行了喷孔内部气液两相流数值模拟。计算结果与国外已有实验数据的对比表明所建模型是正确的,在此计算模型框架下分析了喷孔上下游压差和喷孔入口圆角半径、喷孔直径和长度等几何特征参数对喷孔内空穴区域分布的影响,进而分析了对喷雾特性的影响。

Based on the analysis of the phenomenon of cavitation flow in the nozzles of diesel injection, a two-dimension and two-phase model of cavitation flow in nozzle was developed for a well-developed cavitation flow and the simulation on gas-liquid two-phase flow was conducted. The calculated results from the model have good agreement with the experimental results available in the literatures. With the model the effect of pressure difference between upstream and downstream, the corner radius of the nozzle inlet, the nozzle hole diameter and length on the cavitation location in injection nozzle and the spray characteristics were analyzed.