A combined experimental and computational investigation of an inducer’s characteristics with gas-water two-phase flow

The objective of the paper is to investigate the internal flow characteristics inside the inducer under the gas-water condition using a combination of experiment and numerical simulations. Gas-water mixing is achieved by an annular gas mixing device and visualized by high-speed imaging technology. Meanwhile, the shear stress transport (SST) k- ω model coupled with the VOF model is applied to investigate the gas phase distribution. Numerically simulated inducer energy characteristics and internal gas-phase distribution are in good agreement with experimental data. The results show that the mixed gas-liquid flow inside the inducer exhibits three flow patterns: wavy flow, bubbly flow, and plug flow. For the wavy flow, a series of wavy structures on the blade surface and gas-pocket bubbles near the blade rim are observed. From wavy flow to bubbly flow, uniform bubble streams on the blade surface and spiraling strip bubbles near the edge of the blade are observed. For plug flow, bubble accumulation results in a bullet-shaped plug, and the strip-shaped bubbles near the blade rim are more obvious. In the same axial position of the inducer, the proportion of gas phase is increasing as the flow coefficient increases, thus affecting the inducer performance. The main frequency amplitude of the pressure pulsations gradually rise when the flow pattern changes from wavy to plug flow.