三维喷动床气固两相流数值模拟

Numerical simulation of a 3-D gas-solid flow in a spouted bed

叙述了采用颗粒离散和计算流体动力学相结合的方法模拟三维喷动床流化结果.单颗粒运动通过牛顿第二运动定律进行求解,气体运动通过求解N-S方程.气固两相之间的耦合是由牛顿第三运动定律来实现.模拟床体尺寸为0.11×0.012×0.9m,在单一喷口,入口风速22m/s条件下,对2000个颗粒直径为5mm、密度为2700kg/m3的颗粒进行了模拟.结果表明:在3D喷动床中,颗粒存在宏观运动,中心区颗粒自下而上运动,近壁区颗粒自上而下运动,中心区和近壁区的颗粒运动构成了床内颗粒整体循环运动;在靠近底部的近壁处,颗粒运动存在一定的滞止区.

The paper presents a computational study of the gas-solid flow in a three-dimensional spouted bed by a combined approach of discrete particle method and computational fluid dynamics （DPM-CFD）, in where the motion of individual particles was obtained by solving Newton＇s second law of motion and gas flow by the Navier-Stokes equation based on the concept of local average. The coupling of the discrete particle with continuum gas was achieved by applying the principle of Newton＇s Third Law of Motion. This is done by a series numerical test of 2000 particles with particle density of 2700kgm-3, and particle diameter of 510-3m in a central jet spouted bed of dimensions 0. 110. 0120.9 m. It was shown that the motion of particles man form a circulation between center zone and boundary zone of the 3D spouted bed in macro, and there was a stagnant zone near the bottom of the bed.