自吸泵自吸过程瞬态流动的数值模拟

为研究自吸泵的瞬态气液两相流动过程,应用VOF多相流模型并结合滑移网格技术,采用标准k-ε湍流模型,以泵的进口速度实测值为边界条件,对型号为65ZB-40C的外混式自吸泵自吸瞬态过程内部流场进行了数值模拟.将叶轮分为8个区域,将蜗壳划分为10个断面并设定监测点,分析自吸过程中自吸泵叶轮各区域、蜗壳各断面监测点及其他关键监测面的压力、体积含气率及速度的变化过程.结果表明:在自吸初期和末期,泵内部多数区域压力和体积含气率存在着一个迅速变化过程,叶轮进口、蜗壳各断面、回流孔及气液分离室进口处的速度在自吸初期存在振荡,表现出明显的瞬态效应.所采用的模拟方法能够对自吸泵自吸过程各参数进行初步预测,研究结果对于自吸泵的自吸过程内部流动特性进一步研究具有一定的参考价值.

Numerical simulation of transient flow in self-priming centrifugal pump during self-priming period

The transient air-water two-phase flow field in 65ZB-40 self-priming centrifugal pump du-ring self-priming period was simulated numerically by using the standard k-ε turbulence model, VOF multi-phase model, sliding mesh technique and the velocity profile measured at the inlet of the pump to disclose self-priming mechanism. The transient pressure, velocity and void fraction of the two-phase flow in the pump were acquired at 10 monitoring points in the volute and in 8 zones inside the impeller. The results revealed that the pressure and void fraction experience a rapidly transient process in most area of flow field inside the pump at the early and late stages of self-priming period. At the early stage of self-priming period, the velocity at the impeller entrance, in the cross-sections of volute, reflux hole and inlet to the air separation chamber oscillates, showing a dominated transient effect.