Study on the effect of leading edge erosion evolution on flow characteristics of subsonic and supersonic airfoils

The evolution of aviation engine fan blade leading-edge erosion characteristics with operating time was studied. Identifying the evolutionary features of the eroded leading edges facilitates the investigation of their impact on aerodynamic performance throughout the blade’s lifecycle. This paper constructed four distinct evolution models for eroded leading edges of subsonic and supersonic fan blades based on experimental measurement data. The underlying flow mechanisms were analyzed through unsteady numerical simulations. The results demonstrated that the combined effect of the irregular leading-edge geometry and chord reduction significantly influences the total pressure loss in the flow field. For subsonic airfoils: as erosion severity increases, the energy proportion of higher harmonics in the lower-order modes rises. Large-scale vortex structures near the pressure-side leading edge weaken, whereas small-scale wake vortices strengthen. The mutual induction and stretching between vortices intensify, leading to increased flow unsteadiness. For supersonic airfoils: the eroded profiles SUP-STG2 and SUP-STG3 generate additional coherent structures downstream of the passage shock. The oscillation of the normal shock is also more intense. The flow downstream of the shock exhibits a broad spectrum of high-frequency fluctuations. This reduces the energy of the wake vortices and enhances vortex induction, resulting in greater shock and viscous loss.