Energy harvesting from a vortex ring impinging on an annular ionic polymer metal composite

The energy exchange between a vortex ring and an annular ionic polymer metal composite (IPMC) plate is explored during impact. The vortex ring axis of symmetry is aligned with the geometric center of the annulus, and the ring radius is slightly larger than the hole in the structure. Experimental results show that as the vortex ring approaches the IPMC, the plate initially deflects towards the approaching ring. Upon impact, the plate is pushed away from the impacting vortex ring, while a secondary vortex ring is formed at the edge of the hole, which subsequently propagates away from the IPMC. The mechanical strain of the plate during the impact results in a current through the IPMC, which is measured in order to estimate the energy harvesting capacity of this configuration. This preliminary study suggests that ?0.001% of the initial vortex ring energy can be transduced into electrical energy. An analytical model is developed to assess the energy harvesting capacity as a function of the vortex ring circulation. The model is in good agreement with experimental results, and shows a direct proportionality between the vortex ring circulation and the energy generated by the IPMC.