【摘要】 采用大涡模拟 (LES)方法研究R T(Rayleigh Taylor)不稳定性 ,显示了不稳定发展的小扰动阶段、变形阶段、规则非线性阶段、不规则非线性阶段和湍流混合阶段界面演化与特征 ,分析了湍流混合层厚度增长的规律 ,同时还研究了湍流二阶相关量如动量、质量和能量通量在大尺度和亚格子尺度所占分量 ,验证了LES方法是处理R T界面不稳定性和湍流混合的一种有效方法更多还原

【Abstract】 The Rayleigh-Taylor instability is numerically studied through the Large-Eddy-Simulation (LES) approach.The whole evolution process of the instability is achieved,including the linear stage,the regular nonlinear stage,the irregular nonlinear stage and the turbulent mixing stage.The characteristic of the interfacial motion and the growth of the mixing layer thickness are analyzed.And the averaged turbulent energy as well as the flux of passive scalar is calculated at both the resolved scale and the subgrid scale.The LES method is proved to be an effective approach for the simulation of the Rayleigh-Taylor instability.更多还原