CFD-Based Matched-Point Transonic and Supersonic Flutter Computations Using a Modified TSD Equation

Abstract

In this study, a flutter analysis system in the frequency and time domain has been developed. Flutter analyses for the wing models with previously available wind-tunnel test data have been conducted and the results were compared in the subsonic, transonic and supersonic flow regimes. The nonlinear computational method with potential based CFD technique is applied to obtain the flutter solutions and detailed aeroelastic responses. An efficient unsteady transonic smalldisturbance (TSD) code has been developed using CFD technique and also incorporated into the coupled-time integration aeroelastic solver. Present TSD code is a very efficient tool to compute nonlinear transonic flow-fields since it needs only one flow variable known as the small-perturbed potential. Two-different types of wing models with available experimental data have been considered for validation in this paper. The structural finite element equations for the free vibration analyses are solved by the commercial finite element code MSC/NASTRAN and the modification techniques for structural model are applied to increase the similarity of wind-tunnel model. The possible differences of computational results between matched and non-matched point flutter analysis techniques have been newly presented from the comparison of experimental data. This research also shows the numerical results and comparisons of practical flutter analyses using linear panel and CFD techniques for the reliable benchmark wing models with wind-tunnel test data in the subsonic, transonic and supersonic flow regions.