Numerical Simulation of Gas-liquid Two-phase Flow in Emergency Rescue Drainage Pump Based on MUSIG Model

To investigate the gas-liquid two-phase flow characteristics in an emergency rescue drainage pump, the MUSIG model was adopted to analyze the effect of the gas phase on the internal flow characteristics of the pump. The results show that the gas phase predominantly accumulated in the impeller region, with significant tendencies for large diameter bubbles to fragment into smaller diameter bubbles. The bubbles of the impeller blades converged towards the middle zone of the blade near the hub, forming an air pocket that obstructed the flow passage through the impeller. Such findings ultimately resulted in a loss of pump performance. Moreover, as the diameter of inlet bubble increased, there was a greater tendency for the gas phase to converge into a concentration distribution, leading to unfavorable flow conditions in the pump. This phenomenon ultimately led to a decline in pump performance and may have resulted in the loss of water conveyance functionality. Meanwhile, the Ω method was used to investigate the vortex flow within the drainage pump under different gas contents. As the inlet gas volume fraction increased, the vortex area expanded and the vortex tended to fragment into multiple smaller pieces, resulting in the formation of more complex structures.