Effects of hub endwall geometry and rotor leading edge shape on performance of supersonic axial impulse turbine. Part I

Abstract

The paper focuses on methods for an efficiency increasing of supersonic axial impulse turbines. There was chosen the axial turbine stage with axisymmetric nozzles and mean diameter 103.5 mm as the base model for a numerical and experimental investigation. There were chosen two modifications of the base design to provide an efficiency increasing: modification of the rotor leading edge design and modification of the rotor hub endwall design. The effect of these two factors on the turbine efficiency was analyzed separately. A preliminary numerical investigation showed that the rotor hub endwall modification provided an efficiency increasing up to 2% in comparison with the base model. Meanwhile, modification of the rotor leading edge shape did not provided significant efficiency increasing in comparison with the base model.