基于界面追踪法的Kelvin-Helmholtz不稳定性直接数值模拟  

Direct Numerical Simulation of Kelvin-Helmholtz Instability Based on Front Tracking Method

作　　者：过海龙 张莹[1] 李文彬 李培生[1] GUO Hailong;ZHANG Ying;LI Wenbin;LI Peisheng(School of Mechatronics Engineering,Nanchang University,Nanchang 330000,China)

机构地区：[1]南昌大学机电工程学院,南昌330000

出　　处：《内燃机工程》2021年第3期16-25,共10页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(11562011,51566012);江西省自然科学基金项目(20181BAB206031)。

摘　　要：利用界面追踪法对三组分不混溶流体的开尔文亥姆霍兹不稳定性(Kelvin-Helmholtz instability,KHI)进行直接数值模拟。并针对中间流体层密度及黏度、重力、表面张力及剪切力对KHI的影响进行了着重探讨。研究结果表明,理查德森数增大不仅能够抑制界面的演化,同时还会限制界面的退化。除此之外,卷起高度和KHI的增长速率与弗劳德数之间呈正相关关系。表面张力能够抑制KHI向内发展,随着表面张力系数的增大,KHI向内的发展会逐渐变慢。但当波数较小时,表面张力对KHI向上发展的影响很小,且当界面的波数大于4时不会触发KHI的典型形式。剪切力越大,界面卷起高度和增长速率越大。Numerical simulation for the development of Kelvin-Helmholtz instability(KHI)of the three-component immiscible fluids was performed with the front tracking method(FTM).Effects of density and viscosity of intermediate fluid layer,the gravity,surface tension and shear force on K-H instability were studied.Results show that with the increase of the Richardson number(Ri),the evolution of interface and the degradation of interface are inhibited.It is also observed that the Froude number is positively correlated to the billow height and the numerical growth rate.The surface tension can inhibit the inward development of KHI.With the increase of surface tension,the inward development of KHI will gradually slow down.The influence of surface tension on the inward development of KHI is more important than that on the upward development of KHI if the wave number is not very large.Besides,the typical form of KHI is not triggered when the wave number is greater than 4.The larger the shear force is,the bigger billow height and numerical growth rate of interface is.

关 键 词：开尔文亥姆霍兹不稳定性 界面跟踪法 卷起高度 增长速率 界面比较 

分 类 号：TK402[动力工程及工程热物理—动力机械及工程]