Enhanced magneto-aeroelastic flutter energy harvester (MAFEH) design and testing

Magneto-aeroelastic flutter energy harvesting (MAFEH) is a novel technique in ambient wind energy harvesting, because of its special advantage of free of fatigue problems. An enhanced MAFEH is proposed in this work, which is made by a flat rectangular plate wing supported by a plunging magneto-elastic device. The plate wing can have free pitching motion because of no pitching support. A special type of dynamic instability, body freedom flutter, can develop in a quite low airspeed and result in sustained limit cycle oscillation (LCO) due to the nonlinearities arising from magneto elasticity and stall aerodynamics. Coils are wounded around the magnetoelastic device that can transform the mechanical plunging motion of the magnet to electricity efficiently according to inductive effect. A prototype of the enhanced MAFEH is fabricated and tested in a low speed wind tunnel facility. The critical flutter speed is about 4 m/s that is much lower than the previous MAFEH device. The maximum generated peak-peak voltage is 416.8 mV within the test airspeed range from 4 m/s to 7 m/s. The corresponding rms voltage is 103.2 mV. The maximum output rms power can be up to 201.9 μW in the resistive load at the airspeed of 4 m/s.