Piezoelectric Energy Harvesting from von Karman Vortices

In this paper a study of an innovative energy-harvesting system based on a piezoelectric converter to recover energy from an airflow is presented. The converter is embedded as a part of an oscillating beam, and it is used to harvest energy from the vibrations induced by von Karman vortices detached from a bluff body placed upstream. The system has been placed in a wind tunnel in order to measure the converter voltage and the harvested power for different flow velocities and beam orientations with respect to the flow direction. Experimental results confirm the von Karman vortices as the forcing for the beam oscillations. The possibility to optimize the harvesting effectiveness with the proper beam orientation and flow velocity has been demonstrated.