Early warning of noise-induced catastrophic high-amplitude oscillations in an airfoil model (Q6560594)

In this paper the problem of noise-induced tipping of airfoil systems is addressed as a prototype of real systems a (turbulence suffered) two-degrees-of-freedom airfoil model with random loadings is considered as a concrete example to detect the tipping from a low-amplitude oscillation state to a high-amplitude one. First, effects of random fluctuations on the system response are analyzed, which show that noise-induced catastrophic high-amplitude oscillations take place before the bifurcation point of the corresponding deterministic airfoil model. Furthermore, based on the escape probability, the possibility that the low-amplitude oscillation state of the given noisy model jumps to the high amplitude one is analyzed. The new concept of the high-risk region is proposed, which is an efficient early warning indicator to approximately quantify the ranges of the system parameters where noise-induced high-amplitude oscillations may occur. This new method has non-local universal concept of stability compared with the existing early warning indicators and it can moreover provide theoretical guidance for aircraft designers to take measures to avoid such catastrophic phenomena.