亚声速横向气流中液体射流破碎过程的直接模拟  

Direct Numerical Simulations of Atomization Processes of Liquid Jet in Subsonic Cross-Flow

作　　者：刘日超[1,2] 乐嘉陵[2] 杨顺华[2] 郑忠华[2] 宋文艳[1] 黄渊[2] 

机构地区：[1]西北工业大学动力与能源学院,陕西西安710072 [2]中国空气动力研究与发展中心超高速空气动力研究所高超声速冲压发动机技术重点实验室,四川绵阳621000

出　　处：《推进技术》2016年第11期2135-2141,共7页Journal of Propulsion Technology

摘　　要：为研究亚声速横向气流中液体射流柱的变形、弯曲以及其破碎过程,利用LES结合VOF的方法,对射流破碎过程进行了直接模拟。通过计算观察得到射流柱进入到横流气体中后由于RayleighTaylor(RT)不稳定性和Kelvin-Helmholtz(K-H)不稳定性的共同作用迅速发生变形,并形成表面波,同时伴随着细小液滴的脱落,气流在射流柱后方形成涡状结构。在射流柱的迎风面上同时存在两种表面波,即RT表面波和KH表面波。模拟所得液柱纵向初始表面波波长为0.22mm,与K-H表面波波长理论公式计算所得相接近。通过对比射流柱的背风面和迎风面两侧,发现在横向来流中背风面上的大量细小液滴主要是由横向来流对液柱的不稳定性扰动造成迎风面上的液体向背风面方向挤压并剪切,最终脱落造成。In order to deeply research the mechanisms of column distortion,bend and breaking up when a liquid jet was injected into subsonic cross-flow,the method of VOF（volume of fluid） and LES（large eddy simulation） was used to direct simulation of the atomization processes. The spray column begin distortion after spray was injected into cross-flow and yield surface wave due to Rayleigh-Taylor（RT） instability and KelvinHelmholtz（K-H） instability respectively. At the same time,Vortex was formed behind the spray column accompany with a lot of tiny droplets. There are two types of surface wave at the windward of liquid column： K-H wave and R-T wave. The initial wavelength of column wave is 0.22 mm,and it is equal to expressions of K-H surface wave approximately. Droplets after leeward of spray were mostly because liquid of windward was pushed to leeward due to RT instability by cross flow by compare of windward and leeward of spray column.

关 键 词：RT不稳定性 射流柱 首次破碎 雾化 

分 类 号：V231.2[航空宇航科学与技术—航空宇航推进理论与工程]