항공기 터보팬 엔진용 팬 블레이드 설계속도 진동 및 플러터 해석

Abstract

This study presents a comprehensive vibration and flutter analysis of a newly designed turbofan engine fan. The structural dynamic characteristics of the stage 1 and stage 2 fan blades were investigated using finite element analysis, incorporating the effects of rotational speed and blade–hub interaction. A full-annular finite element (FE) model was constructed to more accurately capture the global dynamic behavior, thereby addressing the limitations of simplified cyclic symmetry assumptions. Aerodynamic damping under various conditions was effectively evaluated through CFD-based flutter analysis using the Fourier transformation method, with consideration of multiple inter-blade phase angles (IBPAs). The influence of mesh type, mesh resolution, modal amplitude, and time step on aerodynamic damping was quantified. Comparative results showed strong consistency between single-passage and full annular models, validating the effectiveness of the proposed method. The preliminary fan blade design was found to closely satisfy the required flutter stability criteria at design speed, and additional insights were provided to support future design optimization.