Numerical Simulation of Gas–Liquid Two-Phase Flow Characteristics of Centrifugal Pump Based on the CFD–PBM

Abstract

This work seeks to apply the computational fluid dynamics–population balance model (CFD–PBM) to investigate the gas distribution and flow mechanism in the gas–liquid two-phase flow of a centrifugal pump. The findings show that the numerical simulation accurately captures the bubble distribution characteristics in the process of coalescence and breakage evolution. In addition, comparing the CFD–PBM with the Double Euler, the hydraulic head of the pump are similar, but the efficiency using the Double Euler is much higher—even close to single-phase. This is in contrast to previous experimental research. Then, the unsteady flow usually led to the formation of bubbles with larger diameters especially where vortices existed. In addition, the rotor–stator interaction was a main reason for bubble formation. Generally, it was observed that the coalescence rate was greater than the breakage rate; thus, the coalescence rate decreased until it equaled the breakage rate. Thereafter, the average diameter of the bubble in each part tended to be stable during the process of bubble evolution. Finally, the average diameter of bubbles seemed to increase from inlet to outlet. The results of this study may not only enhance the gas–liquid two-phase internal flow theory of centrifugal pumps, but also can serve as a benchmark for optimizations of reliable operation of hydraulic pumps under gas–liquid two-phase flow conditions.

Analysis of Fluid-Structure Coupling Vibration Characteristics of Pipeline Transporting Bubbly Fluid Medium: With Application to Luxury Passenger Ship Life Area Pipeline

“…Also, it was widely used in the chemistry feld to describe the fow characteristics such as fuidized beds and bubbling towers [30,31]. In addition, in the feld of hydraulic machinery, the PBM model was also applied to the simulation of cavitation in the fow channel of the water pump, which provided a reference for the structure of the water pump [32,33]. Te above examples show that the PBM model can simulate the fow characteristics of the bubbly fuid, and its simulation accuracy can meet the requirements of mechanical structure design optimization.…”

Study on Cavitation Bubble Characteristics in Centrifugal Pump Based on Image Recognition

“…The gas phase distribution in each impeller passage is not uniform, and the gas phase volume fraction in the impeller flow's passage away from the tongue is larger. Zhang Zhongyuan [14] conducted a comprehensive study on gas-liquid two-phase Processes 2023, 11, 3314 3 of 14 flow in pumps through numerical simulations, high-speed cameras, and ordinary cameras. By analyzing the images, the pixel area was converted into bubble diameter, revealing that bubbles closer to the volute wall tended to have smaller diameters.…”

A Three-Dimensional Slip Velocity Model for Water-Lubricated Hydrodynamic Journal Bearings

“…The above method is easy to apply to bearings with simple shapes, as inertial and radial flow are ignored. In contrast, commercial CFD software is gradually becoming an important basis for predicting the static properties of bearings [33] because of the advantages of predicting three-dimensional flow [34][35][36][37] and its applicability to complex geometries [38][39][40][41]. It should be emphasized that the flow in the gap between two concentric cylindrical surfaces is known as Taylor-Couette flow.…”