Analysis of bubble distribution characteristics in a multiphase rotodynamic pump

Abstract

Study of bubble distribution characteristics is the basis to understand the mechanism of gas-liquid two-phase flow in multiphase pumps. In the present work, a method based on Eulerian-Eulerian approach was used for the simulation of the flow in a multiphase rotodynamic pump. The bubble size was calculated through a bubble number density equation. The distribution characteristics of bubbles were analysed in conditions of different inlet gas volume fraction (IGVF). The results show that bubbles move to the hub and a homogeneous bubble size distribution can be observed due to the rotational effect and stirring action of the impeller blades. The bubble size increases in the vicinity of interaction region because of the rotor-stator interaction. Collision rate of bubbles increase and a large bubble size is shown in the diffuser, which is resulted from the decrease of bubble velocity. It is found that high IGVF cause small distance between bubbles so that collision rate of bubbles increase. Largest bubble size and gas volume fraction are obtained when IGVF is 15%.