两相湍流色噪声扩维法PDF模型及数值模拟

A Two-phase Turbulence PDF Model with Expanding Dimension Method of Colored Noise and Simulation of Wall-jet-flows

由颗粒运动的朗之万方程出发,对流体脉动速度采用扩维方法,得到两个不同层次的PDF输运方程.通过对颗粒运动方程求解和高斯分布假设,解决PDF方程的封闭问题,获得颗粒二阶矩模型,然后将颗粒应力方程简化成代数方程,建立代数应力模型.将对流扩散方程的有限分析法运用到求解两相流模型中,对壁面两相射流进行数值模拟,对比分析数值结果与实验结果.

With Langevin equation of particle motion, PDF equations in two levels are obtained in which the fluid fluctuation velocity is expanded in dimension and one-dimensional colored noise is transformed into two-dimensional white noise. They are two-phase PDF transport equation of turbulence and particle-phase PDF transport equation. With particle motion equations and assumption of Gaussian distribution, a closure problem of PDF equation is solved and a second-order-moment model is obtained. It is simplified into an algebra stress model [ ASM ]. A finite analytic numerical method for convective diffusion equation is applied to solve the two-order moment model of two-phase flows. A wall-jet-flow loaded with solid particles is studied in the ASM by finite analytic numerical method. Numerical results are compared with experimental results.