Intermittency in a Pitch-Plunge Aeroelastic System

This chapter focuses on investigating the phenomenon of intermittency in the dynamical behavior of aeroelastic systems. To that end, a classical two degree-of freedom pitch plunge aeroelastic system is considered as the representative aeroelastic model. Investigations are first carried out on the route to aeroelastic flutter in fluctuating flow conditions through wind tunnel experiments. The recurring nature of intermittent periodic bursts observed in the pre-flutter response are subsequently utilized to develop quantitative measures using time series based tools, that can serve as precursors to flutter instability. To gain further insights into the experimental observations, numerical investigations are carried out using a well known two degree-of-freedom pitch plunge mathematical model for the aeroelastic system. A stochastic bifurcation analysis is also carried out that provide insights into the noise induced dynamical stability characteristics. Finally, a detailed study is undertaken to investigate the physical mechanisms that lead to the appearance of intermittency. Particularly, the effect of time scales of the flow fluctuations are investigated.