Study on the Internal and External Characteristics of the Centrifugal Pump with the Impeller of Columnar Passages

In order to investigate the performance of the centrifugal pump with the impeller of columnar passages, a centrifugal pump with the impeller of columnar passages with a ratio of 17 speed was preliminarily designed based on the design method of partial flow pump, and the high-precision unsteady numerical simulation of the full-flow field was carried out by the detach eddy simulation (DES) turbulence model, and the change law of the internal and external characteristics of the centrifugal pump with the impeller of columnar passages under different working conditions was discussed. The results indicate that within a certain range, the sensitivity of the pump head to the flow change is weak, which is in line with the variable flow and constant pressure characteristics of some flow pumps; the maximum pump efficiency is achieved at 1.7Q_d condition; in the whole working range, there are stall vortices at the columnar passages inlet, and the stall vortex strength is negatively correlated with the flow rate; the fluctuation amplitude of the pressure gradient and relative velocity in the columnar passages increases with the increase of the flow; the pressure pulsation at the columnar passages inlet, near the volute throat and in the diffusion tube shows a trend of first rising and then falling with the increase of flow. That is, the pressure pulsation at the columnar passages entrance and near the volute throat reaches a maximum near the 1.7Q_d condition, and the pressure pulsation in the diffusion tube reaches a maximum near the 1.4Q_d condition; with the increase of the radius, the pressure pulsation in the columnar passages gradually decreases, and decreases the fastest in the radius of 0.04 m to 0.06 m, up to 55%.