A Numerical Investigation of the Influence of Diffuser Vane Height on Hydraulic Loss in the Volute for a Centrifugal Water Supply Pump

The energy efficiency of water supply systems in high-rise residential buildings has become a significant concern for sustainable development in recent times. This work presents a numerical investigation on the influence of diffuser vane height on flow variation and hydraulic loss in the volute for a water supply centrifugal pump. Experiments and numerical simulations were conducted with four different vane height ratios. The numerical results were validated against experimental data. The hydraulic losses of different flow components were numerically evaluated at varying guide vane blade heights. The changes in flow patterns within the volute and the resulting discrepancies in hydraulic losses due to variations in the inlet flow conditions at different blade heights were studied. The findings indicate that the total pressure drop within the volute is affected significantly. Compared to traditional guide vanes, the reduced height vanes can reduce the hydraulic loss in the volute by nearly 75%. Once the vane height is reduced, the high-pressure gradient is improved, and the small-scale vortex vanishes. The influence area of the large-scale vortex in the volute outlet pipe decreases, leading to a weakening of the deflection of the main flow and ultimately resulting in reduced hydraulic loss.