CFD-Based Techniques for Flutter Prediction Through the Generation of Generalized Aerodynamic Forces

This study presents a high-fidelity computational framework for flutter prediction based on generalized aerodynamic forces (GAFs) derived from computational fluid dynamics (CFD) simulations. A reduced-order modeling (ROM) approach is employed, using a pulse excitation strategy to characterize the unsteady aerodynamic response of a structure across a wide range of reduced frequencies. The proposed methodology allows for the computation of GAFs in the frequency domain through a single unsteady simulation per structural mode, providing considerable computational savings compared to traditional harmonic analysis techniques. The simulation framework is implemented within a Python-based fluid-structure interaction environment that couples the open-source CFD tool SU2 with external structural solvers such as MSC NASTRAN. The AGARD 445.6 wing is a benchmark case for validating the methodology by comparing computed generalized aerodynamic forces and flutter speeds against experimental data and results from the literature across a range of Mach numbers.