基于VOF方法分析离心式喷嘴结构参数对性能影响

基于两相界面追踪流体体积(volume of fluid,简称VOF)方法模拟了离心式喷嘴内部的流动过程,在数值方法可靠性验证基础上,得到了15个喷嘴构型的流量系数、液膜厚度以及雾化锥角.定义无量纲影响因子η,比较喷嘴结构参数对喷嘴性能的影响程度.除了喷嘴直径和旋流室直径外,重点研究了出口扩张角、等直段长径比等结构参数的影响,通过与试验相对比,综合以往经验公式,得到如下结论:增大旋流室长度,能够增大雾化锥角;在喷嘴出口增加扩张角,能够显著地减小液膜厚度,减小雾化锥角;增大切向口距喷嘴顶部距离,能够改善喷嘴性能;切向口个数和等直段长度对喷嘴性能影响不大.该工作为下一步优化喷嘴构型打下了基础. 

Analysis of geometric parameters influence on pressure swirl injector performance based on VOF interface tracking method

Interface tracking method volume of fluid (VOF) was used to simulate the flow process in pressure-swirl injector.Three target values including discharge coefficient,film thickness and spray cone angle were obtained after validating the reliability of numerical method.Non-dimensional influence factor η was defined to evaluate the influence of the 15 geometry parameters.The focus is on the geometry parameters which have not been researched much before,such as divergent angle,the length of swirl chamber and so on.The extention of the length of swirl chamber increases spray cone angle.Divergent angle at the injector exit decreases sheet thickness and increases cone angle remarkably.Increasing the distance between the injector and the top wall enhances injector performance.The number of tangent inlet and the length of central post dont not have much to do with the injector performance.What have been done in this paper helps to optimize the injector geometry.