Analysis of bubble distribution in a multiphase rotodynamic pump

Abstract

Recent researches show that the pressure increment of a multiphase pump is affected by bubble size and distribution. In order to study the bubble distribution characteristics in such pumps, a novel approach describing the variable bubble size in the pump is proposed. The bubble number density equation, which has taken into account the phenomena of break-up and coalescence, is introduced into the flow simulation, and the drag coefficient is revised because of the interaction of multiple bubbles. The reliability of the approach is verified by comparison with the experiment. It was established that the bubbles move to the impeller hub due to the difference in centrifugal force between gas and liquid. Despite the high collision rate near the hub, bubble size changes little with the stirring action of the impeller. The mixture flows in a disorderly way and the bubble diameter increases due to the rotor-stator interaction. Owing to the increasing flow area in the diffuser, bubbles move to the mainstream region, and bubble size reaches its maximum owing to the flow separation near the hub. The distribution of bubbles is also analyzed under a different inlet gas volume fraction (IGVF) and inlet bubble diameter (d 0). Bigger IGVF brings about a higher collision rate of bubbles, while smaller d 0 makes the diffusion of bubbles easier.

Effect of incidence angle on cavity blockage and flow stability in the net positive suction head drop of mixed-flow pumps

“…Moreover, lots of studies 18,19,26,[42][43][44][45] had verified the initial values of the empirical coefficients in the cavitation state for several decades to perform 3 D steadystate and transient analysis. The other studies [21][22][23][24][25] that performed visual comparisons with the computational phenomenon using these empirical coefficients also appeared to predict the quite accurate distribution of the cavity. Figure 3 shows the flow chart for the cavitation analysis of this study.…”

“…[18][19][20] The application of this turbulence model also has strong reliability to be a highly accurate prediction for the distribution of the cavity in a number of advanced studies. [21][22][23][24][25] For the twophase transition, the homogeneous mixture model in CFX was employed as one of the most common approaches to deal with the cavitation. 19,[26][27][28][29] It states that the velocity, temperature, and pressure between the phases are equal.…”

Optimizing the Clearance Fit of a Progressive Cavity Pump for the Thermal Recovery of Petroleum Using Fluid–Structure Thermal Coupling

“…The temperature distribution and deformation of the stator are simplified as a process of thermal structure coupling, − ignoring the influence of the pressure and convective heat transfer of the fluid. The temperature field of the stator rubber is regarded as a heat conduction problem with an internal heat source by using the one-way decoupling of its thermodynamics.…”

Transportability Improvement of a Gas–Liquid Rotodynamic Pump Using the Two-Step Multi-Objective Optimization Strategy

“…The internal flow in the gas-liquid rotodynamic pump is complicated because of the high-speed rotating effect of the impeller, the rotor-stator action, and the phase interaction (Zhu and Zhang, 2017;Li et al, 2019). The complex multiphase flow is usually accompanied by the merging and splitting of bubbles and phase content pulsation (Barrios and Prado, 2011;Cubas et al, 2020).…”