Experimental Characterization of Two-Phase Flow Centrifugal Pumps

In this experimental work, the pressure distribution was measured in a rotating, partially shrouded, open, radial impeller, inlet diffuser and volute under a wide range of air-water two-phase flow conditions. To obtain these pressure measurements, small-diameter pressure-tap holes were drilled through the casing of the radial pump. High speed photography was the vehicle to determine the flow regime of the air-water mixture through the vane and in the volute. An analytical model was developed to predict the radial pump single- and two-phase flow pressure distributions. The distribution for the latter was compared with the test data for different suction void fractions. The physical mechanism responsible for pump performance degradation was also investigated.