基于Lagrange方法封闭的两相湍流场方程模型

A Field-Equation Turbulence Model Closed By Lagrange Method

两相湍流场方程模型采用基于Euler方法的一阶矩方程,而二阶矩方程由Lagrange方法得到,新模型的封闭不需要附加其它假设.首先基于概率密度函数给出颗粒运动的连续方程和动量方程,其次由基于平均Langevin方程的Lagrange模型推导得到颗粒二阶矩方程,最终获得封闭的二阶矩模型.将新模型用于气固两相壁面射流的数值模拟,结果表明新模型合理有效.

First-order moment equations of hybrid second-order moment model are obtained by Euler method,while second-order moment equations are deduced by Lagrange equations. Equations for particle fraction and momentum are provided firstly. A Lagrange model with mean Langevin equations is obtained and Reynold stress equation is deduced,so that hybrid second-order moment model is closed without additional approximate assumptions. Wall-jet-flow loaded with solid particles is simulated. It shows that the model is effective.