Research on Radial Force of the Volute Pump with Stay Vanes at Medium-high Specific Speed

Abstract

In this paper, to study unsteady hydraulic excitation characteristics of the impeller in stay vane volute pump, the radial force of that is investigated by vector analysis, time-frequency analysis and unsteady flow field analysis etc. Results show that the radial force distribution on the impeller has a linear relationship with the number of the blade under high flow conditions. Furthermore, the radial force has obvious directivity under low flow conditions. The radial force of the impeller is mainly distributed on the blade and the shroud. Interestingly, it is found that the radial force on the impeller is smaller than the radial force on the blade and shroud respectively, when there are cross peaks between the blade and the shroud. In addition, the results of the unsteady flow field analysis reveal that the radial force distribution of the impeller is unbalanced under low flow conditions. This result is due to the fact that jet wake forms at the impeller outlet and radial vortex leads to rotating stall in the flow channel. This work may provide some theoretical references for the optimal design and stable operation of the stay vane volute pump.