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基于颗粒相动力学理论 ,对层流机制表达的气固两相流体力学模型采用Reynolds平均的方法获得气固两相流的湍流模型描述 .其中 ,气相湍流行为以k -ε模型描述 ;颗粒相的碰撞行为以颗粒流的动力学模型表达 ;而湍流行为以kp 模型描述 .因此建立的k -ε -Θ -kp 模型综合考虑了气相和颗粒相的湍流运动以及颗粒的碰撞行为 .依据此模型建立了三维流体力学求解程序并对下行床气固两相流动行为进行了模型预测 .讨论了恢复系数的选取及壁效应假设 ,从机理上分析并考察了 3种模型的预测能力 .针对内径 1 40mm、高 7m的下行床冷态设备 ,在较宽的操作范围内 ,对比了详细的颗粒浓度和速度径向分布以及轴向参数分布 ,并对下行床的放大行为进行了预测 .
Based on the particle-phase kinetics theory, the gas-solid two-phase flow mechanics model of the gas-solid two-phase flow expressed by the laminar flow mechanism is described by using the average Reynolds method to describe the turbulent flow in the gas-solid two-phase flow. And the turbulent behavior is described by the kp model. Therefore, the established k -ε-Θ-kp model considers both the turbulent motion of the gas phase and the particle phase as well as the collision behavior of the particles. Based on this model A three-dimensional hydrodynamic solution program was established and the gas-solid two-phase flow behavior in the down-bed was predicted.Secondly, the selection of recovery coefficient and the wall effect hypothesis were discussed, and the predictive ability of the three models was analyzed and investigated theoretically. 40mm and height 7m, the detailed radial distribution of particle concentration, velocity and axial parameter distribution were compared in a wide range of operating conditions, and the amplification behavior of the descending bed was predicted.