Stochastic Stability of Linear and Nonlinear Fluid Structure Coupled System with Non-Gaussian Multiplicative Noise

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 nonlinearity, the phenomenon is modified and there is a Hopf bifurcation and limit cycle oscillations. A previous study has shown the important effects of the noise when modeled through a Gaussian process. Based on a recent simulation method, we propose here to study the impact of the noise distribution on stability, considering non-Gaussian distribution for the multiplicative noise.