Effect of blade wrap angle in hydraulic turbine with forward-curved blades

Hydraulic turbine is used for recovering power by using reverse running pump. In order to improve the efficiency of turbine working condition, the impeller with forward-curved blades was applied instead of the impeller with backward-curved blades. The effects on the performance of hydraulic turbine and inner flow character with different blade wrap angles were studied by the method of numerical simulation. The results show that: with the blade wrap angle growth, the maximum efficiency increases, but the range of the flow rate at the high efficiency decreases rapidly; the flow state of hydraulic turbine which in small flow area obtains a remarkable improvement; the flow within the impeller improves and the friction loss increases; the hydraulic loss in the small flow area inside the impeller declines but it grows in the large flow area.