Pressure Fluctuation Downstream of Diffuser Pump Impeller.

Abstract

Instantaneous pressures were measured on the casing wall of a guide vane passage and volute casing of a diffuser pump in order to investigate the interaction between impeller blades and diffuser vanes. The pressure fluctuations were discussed using statistical analysis as well as the ensemble-averaging technique. Frequency spectra of unsteady pressure data show that the dominant frequencies are the impeller blade passage frequency and its higher harmonics. Moreover, the ensemble-averaged pressure data show the spatial distribution of unsteady pressures, which illustrates the rotation of the circumferential pressure mode due to rotor-stator interaction.