通过翻转试验对瑞利-泰勒不稳定性(Rayleigh-TaylorInstabilities)引致的湍流混合过程进行实验研究,提出以染料浓度测定法结合数字图像处理技术测量确定混合物前锋的扩散位置和系数,以拉格郎日块体法(LBM)的数值格式和改进的Smagorinsky理论模式对实验过程进行了大涡模拟数值计算,修正了Voropayev用目测法测量的系数,数值模拟的结果与实验测量结果符合较好。

The Rayleigh-Taylor instabilities were initiated in the laboratory by the sudden overturning of a tank of initially stably stratified fluid of two layers. For flow visualization, dye was introduced as tracer in one of the fluid layer. The concentration of the dye tracer across the highly irregular turbulent interface was measured in the experiment using a video imaging method. The laboratory data of the interface were compared with a Large Eddy Simulation (LES) of the turbulent flow, which was conducted using a numerical scheme known as the Lagrangian Block Method (LBM). The highly irregular turbulent interface was correctly reproduced in the LES by the LBM in close agreement with the laboratory observation.