离心喷嘴内部两相流动及液膜波动特性研究

Characteristics of Two Phase Flow and Liquid Film Fluctuation in Swirl Nozzle

应用界面跟踪方法,RNG(Renormalizationgroup)k-ε湍流模型,对离心喷嘴内部液膜波动特性进行了数值模拟研究.分析了不同的进口速度、燃油表面张力对液膜波动特性的影响.结果表明,离心喷嘴内部充液过程包括非稳态液膜形成过程和准稳态波动过程两个阶段,达到准稳态后,液膜(气核)存在明显的周期性波动特性.随着进口速度的增大,旋转所产生的离心力随之增大,气核尺寸也随之增大,液膜厚度变薄.不同表面张力下气核波动频率变化不大,但幅值不同,表面张力越小,波动振幅越大.

The characteristics of the liquid film in a centrifugal nozzle were numerically simulated by the method of interface tracking and the RNG(Renormalization group)k-εturbulence model.The effects of different inlet ve-locity and fuel surface tension on liquid film fluctuation characteristics were analyzed.The results show that the process of filling liquid inside the centrifugal nozzle includes two stages:the unsteady liquid film formation proc-ess and the quasi-steady state fluctuation process.After reaching the quasi-steady state,the liquid film(aircore)exhibits obvious periodic fluctuation characteristics.As the inlet velocity increases,both the centrifugal force generated by rotation and the air core size increases,and the liquid film thickness becomes thinner.Under different surface tension,the fluctuation frequency of gas nucleus undergoes little change,but the amplitude varies.The smaller the surface tension is,the larger the fluctuation amplitude is.