Aeroelastic Flutter of Wings: Flow Physics, Scaling Laws and Bifurcation Regimes*

Aeroelastic flutter is a problem that is relevant in a wide variety of fields, both due to its detrimental effects as well as its possible utility in applications such as energy harvesting. Aeroelastically mounted airfoils exhibit response regimes that are quite different, and often more complex than flow-induced vibration of bluff bodies. Hence, there is a need for novel tools to aid in the modelling and analysis of this phenomenon. In this work, we report on high-fidelity flow modelling of pitching airfoils using a flow solver that is based on a sharp-interface immersed boundary method. A two-way coupled aeroelastic model of a pitching airfoil is used to demonstrate a variety of response regimes. We examine the effect of various parameters, such as spring stiffness and elastic axis location, on the resulting dynamical response. We extract scaling laws based on the flow physics that predict the onset of flutter, and energy maps are used to gain insights into the various bifurcation regimes exhibited by the system.