ABSTRACT
Harvesting energy from small rivers and other flowing water bodies by means of distributed devices is receiving considerable attention, thanks to their low environmental impact and reduced costs. Piezoelectric materials are quickly developing high efficiency in terms of mechanical to electrical conversion. The main bottleneck of their employment as energy harvester lies in the low efficiency of mechanical energy extraction from a non-pulsating flow. This paper focuses on devices aimed at enhancing flow induced vibrations of an upstream oriented cantilever. The performance of the proposed tip defllectors is assessed by an experimental investigation, carried out in a laboratory flume equipped with an underwater time-resolved Particle Image Velocimetry system. Ceramic perovskite (PZT) piezoelectric patches are bound to the cantilever and provide the frequency response and the potential energy conversion of the system. Results of the experimental campaign elucidate the energy extraction mechanisms of the devices providing support to their optimized design.
