Hard loss of stability and damping effects on flow-induced flutter

This study considers a two-degree-of-freedom spring-mounted flat plate immersed in a flow stream, allowed to perform transverse (heaving) and rotational (pitching) oscillations, and prone to the dynamic instability of classical flutter. Within the energy-harvesting framework, the critical and post-critical response of the system is studied focusing on the influence of the heaving damping, since it can simulate the operation of an energy-conversion apparatus. It has been analytically and experimentally observed that, for certain configurations with elastic centre located at the upstream quarter-chord and a small mass-centre eccentricity downstream of the former, a heaving-damping increment anticipates the instability and increases the pitching amplitude in the post-critical regime, while almost unaffecting the heaving component.