Analysis of the performance and pressure pulsation in a high-speed centrifugal pump with different hub-cutting angles

In this study, the hub cutting of the impeller was presented to suppress the rotor-stator interference between the blade and volute tongue in a high-speed centrifugal pump with double volutes. The flow fields in the centrifugal pumps with four hub-cutting angles 0, 15 degrees, 30 degrees and 45 degrees were numerically simulated to investigate the influence on the internal flow and pressure pulsation using SST k - omega turbulent model. The predicted results of numerical simulation were in good agreement with the experimental ones. The results show that the relative velocity streamline distribution is more uniform and smoother in hub-cutting impeller compared with that in the original one. Also, the head and efficiency of the pumps with hub-cutting impeller are higher than that of the prototype pump, with the maximum increase of 1.97% of the head for the hub-cutting angle 45 degrees under the design flow rate. The pressure pulsation intensity at volute 1 and the unsteady radial force of the hub-cutting pumps are smaller than that of the prototype pump due to the flow improvement. In addition, the maximum and average values of the unsteady radial force decrease with the increase of the cutting angle.