Three-dimensional numerical simulation of the flow inside a radial inflow turbine was presented.Preliminary analysis of the aerodynamic characteristics of the island shaped blade

secondary flow and development of vortex and impact of tip clearance were conducted.Results show that island shaped blade has little sensitivity to flow direction in certain range;secondary flow is evident near the inlet of the impeller and close to the suction surface of the passage;along with the reduction of shroud radius

tip clearance flow of the rotor becomes strong.Appropriate tip clearance flow can improve the flow in the tip region.