Improving the performance of aeroelastic energy harvesters by an interference cylinder

An interference circular cylinder is introduced and placed downstream of the original circular cylinder for improving the output performance of energy harvesting from vortex-induced vibrations. The interference cylinder is fixed, but its spacing distance from the original cylinder can be adjusted. The experimental results show that the harvested power can be greatly enhanced and the bandwidth of the resonance region is also increased depending on the spacing distance and wind speed, compared to the original energy harvester without an interference cylinder. This is attributed to the fact that the flow pattern for the two cylinders changes with varying the spacing distance, resulting in distinctive characteristics of the Strouhal number and coefficients of fluctuating lift force and mean drag force. The present study gives a suggestive guidance in effectively harvesting energy from vortex-induced vibrations by adjusting the spacing distance according to the available wind speed.