Energy Harvesting from Dual Cantilever Flutter

This research highlights the discovery and initial modeling efforts of a flow-induced vibration phenomenon called dual cantilever flutter (DCF) which occurs between two similar adjacent cantilevers exposed to cross-flow. At the proper flow velocity, both beams begin to oscillate and become locked 180 degrees out of phase as they undergo large amplitude persistent vibration near their fundamental resonant frequency. Significant amounts of power can be extracted from DCF over a large velocity range by adding piezoelectric material to the beams.


 

Stall Recovery in Morphing Wings

This research highlights the ability of spanwise morphing wings to be used for stall recovery. Using a nonlinear lifting line model tailored to accurately capture post-stall nonlinear aerodynamic effects, the spanwise variation in camber was optimized to recover to a designed lift in response to a disturbance in angle of attack. This concept draws on the principal that wings do not stall uniformly and thus spanwise morphing wings have a unique ability to target stall locations. The results indicate that the envelope of stall recovery can be extended with the addition of a second degree of freedom within the airfoil in the form of a hinge which can increase the actuation range and induce reflex camber.