Geometry of turbine blade leading edge was altered from circular to non-circular by using the Bezier curves methods

based on which numerical analysis and comparison were made to illustrate how turbine cascade leading edges affected the aerodynamic performance under different attack angles.Within the normal operating range of attack angle (-15°~ +10°)

the non-circular leading edge had a better performance as the gradual increase of the curvature radius of the non-circular leading edge reduced the normal pressure gradient of the leading edge

which further restrained the flow from excessively expanding and reduced the energy dissipation caused by the viscous stress

resulting in a decreased flow loss

and the bigger the curvature radius of the non-circular leading edge

the better the performance.Whereas under the large attack angle of the non-design condition

the gradual increase of the curvature radius would cause more severe cascade separation

which aggravated the loss

and it was exemplified by the case of a five-stage low pressure turbine.Numerical analysis has indicated that the non-circular leading edge can improve the flow features and increase the turbine efficiency.However

for the non-design condition estranging from the design point

the flow attack angle alters so substantially that it has negative effect on the turbine aerodynamic performance.