Rayleigh-Taylor不稳定性诱导湍流混合的数值模拟  

NUMERICAL SIMULATION OF TURBULENT MIXING INDUCED BY RAYLEIGH-TAYLOR INSTABILITY

作　　者：杨玟[1] 王丽丽[1] 张树道[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100094

出　　处：《工程力学》2011年第6期236-241,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(NSAF10676005);中国工程物理研究院科学技术发展基金项目(2008B0101006);国防科技重点实验室基金项目(9140C6901010702)

摘　　要：将传统的k-ε模型应用到RTI引起混合的数值模拟中,模型中起驱动作用的速度梯度由压力和密度梯度取代,给出了合理描述RTI诱导湍流混合特征的湍流产生项的表达式。采用该模型对Youngs和Kucherenko等的常加速度和变加速度条件下的RTI实验进行了数值模拟。通过与实验结果的比较分析,验证了所采用的模型封闭、模型常数、数值算法和程序实现是合适的。在此基础上,进一步探讨了轻重介质密度比、加速度大小以及稳定阶段持续时间对混合的影响。The classic k-Σ model is used to study the turbulent mixing induced by Rayleigh-Taylor instability.In the model,turbulence is driven by its pressure and density gradients instead of its velocity gradient.The expression of the turbulence production term reasonably describing the characteristics of Rayleigh-Taylor instability is given.Experiments of Youngs et al and Kucherenko et al under constant and variable accelerations are simulated by this model.The results are compared with detailed experiment data to prove the validation of the model closure,model constants,numerical algorithm and the implementation of the model used in the paper.On the basis of these,the influences of the density ratio of two materials,the value of acceleration and deceleration time on turbulent mixing are further investigated.

关 键 词：湍流模型 RAYLEIGH-TAYLOR不稳定性 湍流混合 数值模拟 湍流产生项 

分 类 号：O357.5[理学—流体力学]