Energy Harvesting Under Induced Best Conditions

Resonant energy harvesters require for optimum energy conversion an oscillation with resonance frequency. A piezoelectric resonant power converter has been developed. It operates under all circumstances with resonance frequency. The harvester takes the energy out of flowing medium surrounding him. Flowing media can generate forces behind bluff bodies in shape of localized low pressure regions with a high periodicity. These low pressure regions are vortices released from the bluff body in flowing direction. Piezoelectric cantilevers fixed with one end onto a bluff body are used as energy harvesters. If a vortex meets the free end of the cantilever it will be forced to oscillate. This oscillation always occurs with the Eigenfrequency of the cantilever. Since best energy conversion can be achieved in case of resonance with cantilever based harvesters, best conversion conditions are induced by the harvester itself. Former simulations have shown the geometry of the bluff body affects strongly the pressure and the velocity distribution in the flow. Based on those results basic design rules for the dimensions of the cantilever and the bluff body have been developed. Measurements have been carried out in gaseous media     «

Resonant energy harvesters require for optimum energy conversion an oscillation with resonance frequency. A piezoelectric resonant power converter has been developed. It operates under all circumstances with resonance frequency. The harvester takes the energy out of flowing medium surrounding him. Flowing media can generate forces behind bluff bodies in shape of localized low pressure regions with a high periodicity. These low pressure regions are vortices released from the bluff body in flowing...     »