Aerodynamic research of a high-load turbine with novel leading edge fillet considering rim seal

The rim seal can effectively prevent the ingress of high-temperature gas into the gap between the stator and rotor passages. However, the blending of the sealing air and the mainstream will change the flow state in the passage, reducing the turbine efficiency. To improve the flow field and increase efficiency, the PW-E3 incorporates a newly designed fillet at the leading edge of rotor blade, with the fillet bending in the opposite direction to the blade. This leading edge fillet (LEF) organizes the sealing of air in the passage. The variations of the total pressure coefficient (Cpt), pressure coefficient (Cp), and the passage vortex are discussed to evaluate the effect of the fillet at different mass flow ratios. The numerical results show that the application of a LEF effectively mitigates flow losses and subsequently increases the stage efficiency. Moreover, as the fillet height is incremented, there is an observable augmentation in the increasing rate of the stage efficiency. The efficiency growth rate is the largest at a fillet height of 3, with a value of 0.45%. The streamwise total pressure coefficient is decreased under the effects of LEF. And the spanwise total pressure coefficient decreases in the vicinity of the hub end wall. The increasing mass flow ratio of the sealing air reduces the improvement caused by the fillet. The passage vortex is also investigated in depth. It is found that the passage vortex experiences an upward displacement as the LEF lifts the sealing air. As the mass flow ratio of the sealing air intensifies, the scale of the passage vortex undergoes an expansion. Consequently, this elevation of the passage vortex restrains the expansion of the separation bubble on the suction side.