叶片出口角对离心泵内部流动的影响研究OA

To investigate the mechanism of how the blade exit angle affects the internal flow and energy loss in centrifugal pumps,five types of impellers with blade outlet angles of 20°,23°,26°,29°,and 32° were studied.A combined approach of numerical simulation and experiment was adopted to investigate the hydraulic performance,energy loss,and pressure fluctuation of a centrifugal pump,aiming to reveal the underlying correlation between its internal flow characteristics and pressure fluctuations under different blade outlet angles.The results show that at a design flow rate Qd=1.5 m ³/h,as the blade outlet angle increases,the head and shaft power increase,and the efficiency decreases from 69.71%to 69.38%;the high energy loss areas with entropy production rates greater than 20 kW/(K⋅m³)are mainly concentrated at the inlet and outlet of the impeller,the back pressure surface of the blades,and the tongue of the snail shell,and the energy loss in the wake area of the impeller increases with the increase of the outlet angle;the main frequency of pressure pulsation is basically consistent with the shaft frequency,with a maximum decrease of 16.45%in pulsation amplitude at 0.95R0 and a maximum increase of 16.98%at 0.4R0.Based on the comprehensive entropy production and vibration characteristics,the optimal blade outlet angle range is proposed to be between 23° and 26°.Within this range,energy dissipation and pressure pulsation are relatively low,which can provide theoretical reference for the hydraulic design of centrifugal pump impellers.