Force Characteristics of Centrifugal Pump as Turbine during Start-Up Process under Gas–Liquid Two-Phase Conditions

The start-up process of a centrifugal pump as turbine (PAT) under gas–liquid two-phase conditions was simulated based on Fluent, and the evolution mechanism internal flow field variation law force characteristics were studied in its conditions. results show that area with high gas phase concentration corresponds to strong vortex at beginning start-up. intensity impeller gradually decreases an increase rotational speed. volume fraction blade suction surface is more significant than pressure surface. higher inlet (IGVF) is, severely load will fluctuate during process. As speed increases, fluctuation weakens, maximum distributed near inner edge after stable. periodic unbalanced radial produced From pure liquid increasing IGVF, dominant frequency amplitude shows similar trend decreasing first but then increasing. After tends be stable, equal blade. With speed, axial gradually. greater same time.