离心叶轮内宾汉流体的密相两相湍流数值模拟

Numerical simulation of turbulent flow of Bingham fluid in centrifugal impeller

阐述了宾汉流体控制方程的特点,首先对单相的宾汉流体与密相液固两相流进行了计算,计算结果与实验数据吻合较好。其次对离心叶轮内的含颗粒的宾汉流体的两相流动进行了计算,从进口到出口,宾汉流体的速度是减小的,压力随半径增大逐渐升高,而且压力面上的压力大于吸力面上的压力。吸力面上的颗粒拟温度小于压力面上的颗粒拟温度,而且靠近壁面处的大于叶道中的。从减轻叶片磨损角度来讲,双圆弧型线比单圆弧的好,叶片出口角小的比出口角大的好。最后比较了液固两相流与含颗粒的宾汉流体的两相流的流动,颗粒拟温度有较大差别。

The character of the governing equation for Bingham fluid is expounded. First, Bingham fluid single phase and liquid-solid dense two-phase flow are simulated, their results agree well with the experiment data. Then, numerical study on turbulent two-phase flow of Bingham fluid centrifugal impeller is performed. It is found that, from inlet to outlet, velocity is decreased, and that velocity in tension side is smaller than that in suction side. Pseudothermal temperature in tension side is bigger than that in suction side, and pseudothermal temperature near wall is bigger than that in interior. Pseudothermal temperature can be used to describe abrasion level. From the point of view of diminishing the abrasion, we find that blade pump impeller with double arc shape is better than that with single arc shape, pump impeller with small outlet angle is better than that with big outlet angle. Finally by companing the two-phase flow of Bingham-solid with liquid-solid, it is found that the pseudothermal temperature has certain difference.