The Influence of Blade Wrap Angle on the Internal Flow Field and Hydraulic Performance of Double-Suction Pump for Yellow River Pumping

Analyzing the influence of blade wrap angle on the internal flow field and hydraulic performance of the pump, five different blade wrap angles were designed. Based on RNG k-ε and DPM were used to conduct a steady-state numerical simulation of impellers under the same conditions and different sand volume fractions, respectively. The results show that as the blade wrap angle increases, the flow separation and vortices in the impeller flow passage also decrease, and the flow is closer to the blade profile, but the friction loss in the impeller flow passage also increases. There is an optimal blade wrap angle to maximize the pump head and efficiency. By increasing the wrap angle of blade, the low-pressure zone at the blade inlet area increases, the high-pressure zone at the outlet decreases, and the low-speed zone within the impeller decreases, increasing the outlet velocity. When the sand volume fraction is less than 5%, the effect of sand volume fraction on the hydraulic performance of the pump is not obvious. When the sand volume fraction is more than 5%, the change of wrap angle of blade has a significant effect on the hydraulic performance of the pump.