Nonlinear transient Fluid/Structure interaction approach using surrogate models: Industrial application to aircraft fairing vibration excited by engine efflux

The interaction between inertial, elastic and aerodynamic forces for structures subjected to a fluid flow may cause unstable coupled vibrations that can endanger the structure itself. Predicting these interactions is a time consuming but crucial task in an aircraft design process. A method for a fast nonlinear transient fluid structure interaction is presented in this paper. Surrogate reduced order models in both aerodynamic (Singular Value Decomposition) and structural (Component Mode synthesis) models are used to gain computation time. Structural complexities, such as non-linearities, are reintroduced after the reduction process. The nonlinear structural solver is coupled through an efficient C++ interface to a database of pressures generated through Computational Fluid Dynamics simulations and post-processed through a Python-based reduction toolkit. The methodology is applied on a specific aircraft component, the flap track fairing, and results are presented. This paper shows that a combination of structural and aerodynamic reduced order models, interpolation techniques, and an efficient aero-structure data exchange could provide a fast method to estimate non-linear fluid structure interaction during transient response.