适用于内燃机喷雾的新液滴碰撞模型

A New Droplet Collision Model Applied for Spray in Internal Combustion Engines

本文将直接模拟蒙特卡洛(DSMC)方法中的时间计数器(Time Counter,TC)法按照喷雾领域对液滴碰撞模型的要求,对粒子碰撞频率、碰撞域的划分以及碰撞对的选取等方面进行改进。通过模拟结果与实验值的对比,表明相对O’Rourke模型与Nordin模型,TC模型对喷雾宏观形态的预测以及对场内液体体积分数(液滴的空间分布)的计算更加准确;对下游索特平均直径的预测与实验值亦更加贴近。

The Time Counter(TC)method in direct simulation Monte Carlo(DSMC)method was improved according to the requirements of the spray in the droplet collision model.The collision frequency,collision cells division and collision pairs selection were enhanced.The comparison between simulation results and experimental data shows that,compared with the O’Rourke model and the Nordin model,the TC model is more accurate for the prediction of spray macroscopic morphology and the volume fraction of the liquid in the spray(i.e.,droplets distribution).The prediction of Sauter mean diameter by TC model is closer to the experimental value.