PARAMETRIC GEOMETRY CONTROL OF AN AERO-ENGINE FAN BLADE USING A BEZIER-BASED MEAN CAMBER LINE

The aerodynamic efficiency of advanced fan stages of aircraft engines in transonic mode is determined by geometric profiling factors.Specifically, it depends on the distribution of profile curvature.Camber-line distribution has a direct effect on flow acceleration, shock position, pressure recovery, and loading distribution along the chord.This paper presents a parametric geometrycontrol method for fan blade profiles.The mean camber line is described by a fifth-order Bezier curve, while the thickness law is generated using monotonic cubic Hermite interpolation (PCHIP).This combination provides smooth profile construction and avoids non-physical oscillations in the thickness distribution.This allows the chordwise aerodynamic loading to be redistributed in a controlled manner.The thickness is applied in the normal direction to the camber line, which preserves geometric consistency of the upper and lower blade surfaces.The method was tested through numerical simulation of a transonic fan stage.The results show a stable flow pattern, controlled acceleration on the suction side, and gradual pressure recovery downstream of the peakvelocity region.The computed total pressure ratio is 1.36, while the isentropic efficiency reaches 0.88.These results confirm that the proposed parameterization can be used as a reliable basis for further aerodynamic optimization of fan blade geometries.The method also makes it possible to evaluate the practical effect of local curvature changes on the flow structure.