气液固三相逆流湍动床流体动力学特性的三维数值模拟

Three-dimensional Numerical Simulation of Hydrodynamic Characteristics in Inverse Gas-Liquid-Solid Three-phase Turbulent Bed

基于多相流欧拉模型,应用计算流体动力学(CFD)软件Fluent 6.3,数值模拟了轻颗粒流、液体间歇方式进料的三维气液固逆流三相湍动床的流体动力学特性,考察了床内颗粒的轴径向速度和固含率分布规律。模拟发现:床内颗粒流化时存在颗粒的汇集行为;颗粒由床中心向壁面运动,中心附近颗粒径向速度大,壁面附近颗粒径向速度小;颗粒轴向速度分布不均匀,呈"两头小中间大"的趋势;固含率壁面附近高,中心附近低,并随轴向高度增加而减小;床内平均固含率随表观气速或液体黏度的增加而减小。

Based on multiphase Euler model,three-dimensional numerical simulation of hydrodynamic characteristics in an inverse three-phase turbulent bed is carried out with light particle flow and liquid in batch,by computational fluid dynamics software Fluent6.3.The law of distributions of solid holdup and particle axial and radial velocity are obtained.The simulation result shows that there exists accumulation of particles during fluidization.Particles move from bed center to wall,and the radial velocity near the center is bigger than that near the wall.Axial distribution of particle velocity presents that the end and head is small,but near the middle bigger.Solid holdup is lower near the center than that near the wall.Average solid holdup decreases with increasing axial bed height,gas velocity and liquid viscosity.