Reverse modeling strategy of aero-engine blade based on design intent

Abstract

Blade geometry plays an extremely important role in the aerodynamic performance of aero-engine. However, in the process of secondary machining for near-net shape or serviced blade, the deviation between the actual and nominal blades can raise serious problems for NC tool path generation. It is even worse that inappropriate reverse modeling may change the design intent and deteriorate the aerodynamic performance. This paper presents an innovative strategy for reconstructing actual profiles from measured data. Comparing with conventional reverse modeling, the proposed strategy emphasizes functional significance of the known feature information concerned with implicit design intent. The preservation of design intent has three levels by cognition of the feature information. Firstly, the established technique for rigid registration is improved by means of incorporating accuracy feature into localization. Secondly, the parametric design methodology of aero-engine blade profile is introduced into the free-form deformation (FFD) of cross sections to control geometry feature, and finally, it guarantees aerodynamic performance feature. Some practical examples are given to demonstrate the effectiveness and superiority of the strategy.