竖直管道内冰浆流体流动特性的数值模拟

Numerical Simulation of Ice Slurry Flow in a Vertical Pipe

为研究竖直管道内冰浆流体流动特性,采用基于颗粒动力学理论的两相流双流体模型,通过CFD模拟研究了竖直管道内冰浆流体的等温流动过程。结果表明,在竖直管道内冰浆湍流输送过程中,流速沿管道中心轴线处近似呈对称分布。当冰浆流速较低时,管道截面处冰粒子的速度分布梯度较小,浓度分布趋于均匀,而随着冰浆流速升高,冰粒子的流场及浓度场均呈现出一定的梯级分布:管道近壁面处冰粒子浓度较低,而管道中心处冰粒子浓度较高,并在略偏于管道中心轴线位置处冰粒子浓度达到峰值。竖直管道内冰浆流体的流向变化对速度分布影响较弱,但对冰粒子浓度分布会产生一定影响,进而使得冰浆流体的管道压降在不同流向时存在着一定差异。

The two fluids Eulerian model based on the kinetic theory of granular flow has been applied to predict the ice slurry flow in a vertical pipe without considering ice melting process.It can be seen that the ice particle velocity profile is symmetrical along the central axis in the vertical pipe.When ice slurry moves at low speed,the velocity gradient becomes small,and the concentration profile approaches even in the pipe cross section.When the moving speed increases,the ice particle velocity and concentration stratify.The ice particle concentration is relatively small near the pipe wall,but larger close to the central axis with a concentration peak nearby.The flow direction imposes minimal effects to velocity profiles but makes a great impact on particle concentration distribution.In addition,there are meaningful differences in pressure drop when flowing with different directions.