提升管内气粒流动行为的数值模拟

采用描述密相湍流气粒流动规律的k-ε-kp-εp-Θ双流体模型对不同尺度和操作条件下的提升管内的定常流动进行了计算流体力学数值模拟，获取了各种工况下有关颗粒速度、体积分率和质量流率分布等宏观流动行为的大量信息，并与相应条件下的实验数据取得了较好的吻合。此外还通过对大量模拟数据的分析获得了提升管内宏观流动规律的综合图像。该模型描述了密相湍流气粒流动规律，预测出了描述单颗粒脉动能大小的颗粒拟温度田和表征颗粒在介观尺度上脉动大小的颗粒湍动能江在床内的分布。分析表明：不同流动参数对颗粒在微观和介观尺度上的脉动有不同程度的影响；固含率对颗粒相的脉动行为和颗粒的质量扩散行为有重要的影响。

Numerical Simulation of the Gas-Particle Flow Behavior in Risers

The stable gas-particle flow in risers with variant operating conditions was predicted based on a k-e-kp-ep-Q two-fluid model. Much information on the macro flow behavior, such as local particle axial velocity, solids volume fraction and solids flux in different operating regimes was obtained and the predicted results showed satisfactory agreements with experimental data. Further analysis and comparison of the predictions give the comprehension of flow characteristics on the macro scale. The model describes the dense turbulent gas-particle flow. Both the particle pseudo-temperature Q, which is the scale of the fluctuant energy of single particle, and the particles turbulent energy kp, which describes the particles fluctuation in meso scale, can be predicted by the numerical simulation. Further investigations show that different flow parameters influence the particles fluctuation in different ways and that solids volume fraction has significant effect on the particles fluctuation and particles dispersion behavior.