Novel optimization strategy of a flow-induced piezoelectric vibration-based energy harvesting structure

In this paper, a novel boundary layer enhancement structure as well as various bluff body arrangement strategies were proposed to optimize the voltage output performance of a piezoelectric vibration-based energy harvest equipment. A systematic investigation in both numerical and experimental approaches revealed that an inversed 6-cylinder bluff body arrangement yielded significantly better voltage output performance than the previously reported dual-cylinder arrangement. A positive correlation can be observed between both flow velocity and the voltage output, and the cantilever beam tends to oscillate at a slightly higher frequency under a higher inflow velocity. A very noticeable improvement was observed when the proposed wall structure was applied, and our numerical study revealed that the wall structure induced a relatively stable layer of fluid near the wall and led to a much more chaotic wake of the bluff bodies which may account for the performance improvement of the system.