Enhanced piezoelectric galloping energy harvesting using 2 degree-of-freedom cut-out cantilever with magnetic interaction

Most piezoelectric aeroelastic energy harvesters operate effectively only at high wind speeds or within a narrow speed range. To overcome this issue, we propose a 2 degree-of-freedom (2DOF) piezoelectric aeroelastic energy harvester with a cut-out cantilever and two magnets. Translational galloping is induced with a square cross-sectioned bluff body attached at the cantilever tip. Magnetic interaction is introduced to create stiffness nonlinearity. The proposed device is demonstrated by wind tunnel tests to have a lower cut-in wind speed of 1m/s and higher power output than the conventional 1 degree-of-freedom (1DOF) harvester in the low wind speed range up to 4.5m/s.