离心式喷嘴充填过程内部流动特性仿真

基于两相界面追踪方法VOF(volume of fluid)模拟了离心式喷嘴充填过程中的内部流动特性。研究了气液界面随时间的变化过程，发现了充填过程中气核收缩和旋转液膜的现象；通过提取气相体积分数等值线的方法计算了充填过程中喷嘴出口液膜厚度和喷雾锥角的变化。结果发现:液膜厚度随出口流量的增大而增大，出口喷雾锥角随出口流量的增大而减小；描述了喷嘴旋流室内的回流现象，分析了充填完成后的压力场和速度场分布，发现在压降和气液作用的共同影响下，中心气核轴向速度沿轴向先增后减。 

Simulation of inner flow characteristics of swirl injector during the filing process

Inner flow of fluid (VOF) method was applied in the simulation of inner flow characteristics of a swirl injector during the filling process. The resolution of the phase interface was investigated, the phenomena of the shrink of air core and the rotation of liquid film were discovered. The changes of liquid film thickness and spray angle at the injector outlet during the filling process were calculated by extracting the contours of gas phase volume fraction. The results showed that the liquid film thickness increased along with the outlet mass flow rate, while the spray angle decreased. Besides, the circumfluence in the swirl chamber was described, and the pressure field and velocity field were analyzed, indicating the change of the axial velocity was attributed to the co-effect of pressure drop and gas-liquid interaction.