突扩管道中密相两相湍流的数值研究

利用颗粒动力学理论，建立了密相两相双流体湍流模型，给出了其封闭方程组，提出了一个简单而精确的颗粒径向分布函数的计算公式，运用所建的数学模型，系统地研究了竖直向下突扩管道中气固两相湍流的流动计算发现：两相突扩的流动特性与流动突扩比、两相间密度差、颗粒大小、颗粒的平均体积分数等有因素有关；颗粒相的流动特性在某一个颗粒直径下会发生突跃，这个直径的大小是与流动突扩比及两相的密度及粘度有关的。

Numerical Study of Dense Particle-Fluid Turbulent Flow in a Sudden Expansion Pipe

Two fluid turbulent model for two dense phases was set up, based on the particle dynamic theory. The equations with closure law were proposed. A simple function with higher precision was provided. The gas particle two phase downwards turbulent flow in vertical sudden expansion pipe was studied numerically. It shows that the flow characteristics of both phases are relevant to the particle size, the average concentration of the particle phase, the density of particles and the sudden expansion ratio of the pipe. The characteristic of particle flow changes sharply under some critical particle diameter. The diameter depends on the density and the viscosity of two phases as well as the sudden expansion ratio.