Experimental validation of a novel piezoelectric energy harvesting system employing wake galloping phenomenon for a broad wind spectrum

In this paper, a novel piezoelectric energy harvesting system using the wake galloping phenomenon is explored for the broad wind spectrum. Wake galloping is an aerodynamic instability phenomenon which has promising potential in energy harvesting. The offered advantage by the proposed system is having a wider wind speed range for a reliable and sustainable energy source for a small wireless sensor node, in addition to being simple and easily applicable to civil structures. In the proposed system, the flow of wind runs parallel to the placed cylinders with upstream cylinder fixed at one end while the downstream one is placed over an unimorph cantilever beam with piezoelectric film attached to it. To validate the effectiveness of the proposed system, several tests were conducted against wind speeds approaching till 10 m/s with varying cylinder spacing. The results revealed an optimum spacing between two cylinders of 3D and the cut-in speed was estimated to be 4 m/s. The attained results were smartly analyzed to further explore the effect of cylinder spacing on the aerodynamic vibrations and the other associated parameters.