Hybrid finite-volume-ROM approach to non-linear aerospace fluid-structure interaction modelling

Abstract

A fully-coupled partitioned fluid-structure interaction (FSI) scheme is developed for sub- and transonic aeroelastic structures undergoing non-linear displacements. The Euler equations, written in an Arbitrary Lagrangian Eulerian (ALE) coordinate frame, describe the fluid domain while the structure is represented by a quadratic modal reduced order model (ROM). A Runge-Kutta dual-timestepping method is employed for the fluid solver, and three upwind schemes are considered viz. AUSM+ -up, HLLC and Roe schemes. The HLLC implementation is found to offer the superior balance between efficiency and robustness. The developed FSI technology is applied to modelling nonlinear flutter, and the quadratic ROM demonstrated to offer dramatic improvements in accuracy over the more conventional linear method.