颗粒扩散的三个效应分析及其数值模拟

Analysis of three effects of particle dispersion in isotropic turbulent flow and its numerical simulation

在对均匀各相同性湍流中的颗粒进行研究时 ,目前通常采用拉氏方法描述两相湍流中的颗粒相运动 ,用的较多的就是基于颗粒所见气体速度的 Langevin方程。此方程的封闭必须考虑颗粒扩散的轨道穿越效应、连续性效应和惯性效应。在仔细分析几个效应的基础上 ,提出了一种改进的漂移系数模型 ,综合考虑颗粒在均匀各向同性湍流内扩散所遇到的三种效应的影响 ,并进行数值模拟分析了几个效应对于数值模拟结果的影响。

In the course of research of particle phase in the isotropic uniform flow, the Lagrangian method is widely used to describe the particle phase movement of two phase flow. The common model is a Langevin-type equation of the fluid velocity relative to the particles. To enclose the equation, the inertia effect, the crossing trajectories effect and the continuity effect of particle dispersion must be taken into account in the model. On the base of detailed analysis of some effects, a modified model for the drift coefficient was proposed puts, considering synthetically the three effects of particle dispersion in isotropic turbulent flow. Finally the diversification of result of numerical simulations were carried out to analysis the different effect of particle dispersion.