气固两相流动的动力模型

Modeling of Gas Solid Two Phase Flow Using Kinetic Theory

对密相两相流动（εｓ＞０．０１），用通常的两相流动模型来描述会带来很大的误差。本文基于两流体模型，从Ｂｏｌｔｚｍａｎｎ统一微分方程出发，推导出了颗粒相的连续方程，动量方程和湍动能方程，并将粒子的切应力和粘性系数表达成颗粒湍动能的函数，用改进后的混合长度模型来描述气相湍流。本文运用该模型计算了竖直管内两相流动与循环流化床两相流动，并与实验结果进行了比较。

For dense two phase flow ( ε s >0.01), it is difficult to simulate hydrodynamics by using traditional two phase flow model. Based on the concept of “Two Fluid Model”, a predictive two phase flow model, including continuum, momentum, and kinetic fluctuating energy transport equations, are derived starting with Boltzmann integral differential equation in this paper. Here, the stress and the viscosity of solid phase are expressed as functions of solid kinetic fluctuating energy. Also in present work, the modified Prantle Mixing Length Model is used to account for the gas phase turbulence at the presence of particles. Finally, the gas solid two phase flow in the vertical pipe and the riser of circulating fluidised bed are calculated in this paper, which shows good agreement with the experimental data.