Flow Visualization of Centrifugal Pump by the Combination of LIF and PIV

Abstract

The visual experimental system for the centrifugal pump was established. The mock centrifugal pump with six curving semi-open impellers was manufactured by polymethyl methacrylate. The flow characteristics inside the mock centrifugal pump was studied by the combination of laser induced fluorescence (LIF) and particle image velocimetry (PIV). The polyamide resin particles were dissolved into the fluid of the circulation for PIV analysis, and fluorescent dye rhodamine B was head-on injected to the impellers for LIF analysis. The front plane of the impellers was covered by Nd: YAG laser sheet, one CCD camera collected the reflected laser light from the particles. Synchronously, another camera collected the fluorescence of rhodamine B. The velocity distribution characteristic was presented, and the time evolution of injected dye in the channel between impeller and septum was obtained. The inlet fluid moved circumferentially along the impeller under centrifugal force, the central region had smaller velocity. The injected dye gathered into blocks near the central area, and was evenly distributed near the edge of the pump impellers. The combination of LIF and PIV was proved to be credible method in the research of centrifugal pump.