Investigation of Equivalent Reduced Order Models for Flutter Analysis of Various Wing Plate Configurations

This paper presents guidelines for developing an Equivalent Reduced Order Model (EROM) for aeroelastic flutter analysis. The Global Finite Element Model (GFEM) typically involves a denser mesh of elements and nodes, leading to higher computational costs. The EROM is derived from the GFEM based on several prescribed static loading schemes. The study considers three wing plate configurations: untapered-unswept, untaperedsweptback, and tapered-sweptback. The effectiveness of the EROM is assessed in terms of their normal modes and flutter characteristics. The method involves identifying the elastic axis, determining bending and torsional rigidity, and updating the model to match the GFEM's normal mode characteristics. Flutter analysis is then conducted to compare natural frequency and damping trends over a range of airspeeds (V-f and V-zeta). The proposed method effectively lowers the model order, resulting in an approximate 70% reduction in FE structural nodes. The results demonstrate that the developed EROM provides acceptable accuracy, as shown by the low standard deviation in the differences of flutter speed (Delta Vf) and frequency (Delta Ff) between the EROM and GFEM, which are within +/- 0.59 m/s and +/- 0.60 Hz, respectively. Additionally, the V-f and V-zeta plots also indicate comparable trends between EROM and GFEM.