Numerical Investigation of Turbulence Production Under Two-Phase Flow in a Simulation of Electrical Submersible Pump Performance
Abstract
Investigating the characteristics of gas–liquid two-phase flow in a centrifugal pump is critical for evaluating pump performance. In this study, a numerical simulation was performed to understand the effects of gas–liquid turbulence formation in the impeller channels on the performance of a single-stage centrifugal pump. The focus was on the inlet gas volume fraction (IGVF) at constant flowrate and constant impeller speed on the flow structure in the impeller and the pressure surging characteristics. The correlation between Reynolds shear stress and turbulent kinetic energy on pump performance is shown by examining pressure, velocity, turbulent kinetic energy, and gas volume fraction (GVF). The model verification is verified using the theoretical pump pressure head determined by the manufacturer, which demonstrated adequate uncertainty (μ< 5%) for a flowrate of 250 L/min. The results show a 9.41% decrease in wall shear stresses when the in-situ GVF varies between 1% and 10%. Wall shear stresses combined with circulation resulted in a 3.76% decrease in turbulent kinetic energy, while the contribution of turbulence to pump performance degradation is minimal. Other factors such as gas entrapment, impeller inlet blockage due to bubble coalescence, pressure gradient, and bubble size had a much greater impact on performance. The performance decreased dramatically by 26.53% when the GVF increased from 1% to 10%. The proposed flow structure can be further investigated together with the wall shear stress and circulation phenomena, such as vorticity and shear layers in the context of two-phase flow.