A linearized method for the frequency analysis of three-dimensional fluid/structure interaction problems in all flow regimes Original Research Article

We present a computational fluid dynamics (CFD)-based linearized method for the frequency analysis of three-dimensional fluid/structure interaction problems. This method is valid in the subsonic, transonic, and supersonic flow regimes, and is insensitive to the frequency or damping level of the sought-after coupled eigenmodes. It is based on the solution by an orthogonal iteration procedure of a complex eigenvalue problem derived from the linearization of a three-field fluid/structure/moving mesh formulation. The key computational features of the proposed method include the reuse of existing unsteady flow solvers, a second-order approximation of the flux Jacobian matrix, and a parallel domain decomposition-based iterative solver for the solution of large-scale systems of discretized fluid/structure equations. While the frequency analysis method proposed here is primarily targeted at the extraction of the eigenpairs of a wet structure, we validate it with the flutter analysis of the AGARD Wing 445.6, for which experimental data is available.