Abstract Numerical simulation was adoped and the blade wrap angles were 45°, 65°,75°,85°,95° and 105° when impellers′ other geometric parameters remained the same. We studied how the change of the blade wrap angles influences PATs. The results show that with the increase of the blade wrap angles, the liquid flow is closer to the blade profile. The vortex in the impeller channel inside in improved. The turbine′s high-efficiency curves shift toward the small flow rate area, the high efficiency region becomes smaller and the head curve and shaft power curve are getting steeper. The blade′s constraint on the flow is enhanced with the increase of blade wrap angles, so that the hydraulic loss in the small flow area is reduced, but the runner is lengthened, so that the friction loss is increased. With the augment of the blade wrap angles, the hydraulic loss increases in the mass flow area so that there is a best blade wrap angles. This result can provide some guidance to the design of the mixed-flow pump as turbines.
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