Stochastic Stability of Fluid-Structure Coupled Systems with Multiplicative and Additive Noise: Application to Airfoil Flutter

摘要

This paper is concerned with the investigation of stability of fluid-structure coupled systems in turbulent flow. The field of turbulence is modeled by stationary stochastic processes and may introduce multiplicative as well as additive noise in the original deterministic formulation. The stability of the so obtained random dynamical system is investigated by the means of Lyapunov exponents. It is well known that a linear airfoil subjected to a fluid flow (no turbulence) may exhibit flutter instability for a certain flow velocity. Taking into account a structural freeplay non-linearity, the phenomenon is modified and there is a Hopf bifurcation and limit cycle oscillations. We propose to study the impact of noise i.e. (atmospheric) turbulence on these phenomena.