超声速流动中非线性EASM湍流模式应用研究

摘要

To meet the needs of simulating complex supersonic flow regions accurately,the nonlinear explicit algebraic Reynolds stress model (EASM) based on the form of k-ω compressibility modification is developed.The numerical simulation accuracy of the model for supersonic flow is improved.The flows of 2-D supersonic cavity and 3-D hypersonic double ellipsoid are calculated by EASM.Compared with the conventional linear eddy viscosity models(SA and SST turbulence models),EASM has the potential ability to describe the flow structure of massive separation and shear layer in more sophisticated detail and simulate pressure and friction coefficient distribution in the region where shear layer reattaches more precisely.Distribution of pressure and heat flux induced by secondary shock wave are simulated accurately.%针对超声速复杂流动区域精确模拟的需要,发展了基于k-ω可压缩修正形式的非线性显式代数雷诺应力模式(EASM),提高了该模式对超声速复杂流动的数值模拟精度.通过对二维超声速凹槽和三维双椭球的数值计算表明,与SA和SST常规线性涡黏性湍流模式比较,非线性的EASM模式对大分离以及剪切层流动结构的刻画能力更精细,对剪切层再附区的压力及摩擦系数分布模拟更加精确;EASM模式能够准确地模拟二次激波引起的压强和热流分布情况.