Use of half-cylinder obstacle for enhancing aeroelastic energy harvesting

Abstract

ABSTRACT This study aims to improve the performance of the galloping-based piezoelectric energy harvester (GPEH) by benefiting from two half-cylinder obstacles. Two half-cylinder obstacles are employed to construct a variable cross-section tube which changes the airflow characteristics near the GPEH placed inside. The performance of the GPEH in the variable cross-section tube is tested by wind tunnel experiments. The experimental results demonstrate that compared with the traditional GPEH, the cut-in speed of the GPEH with the two half-cylinder obstacles at the downstream position −1.5D is reduced by 43.87%, from 2.23 m/s to 1.55 m/s. For the highest experimental wind speed of 4.29 m/s, the output voltage of the GPEH with the two half-cylinder obstacles is increased by 109.28%, from 4.31 V to 9.02 V. Moreover, the performance of the GPEH with the obstacles can be improved by appropriately increasing the obstacle curvature and reducing the throat width. The computational fluid dynamics (CFD) simulations are conducted to qualitatively interpret the experimental discoveries. The results demonstrated that the downstream area is beneficial to the GPEH, whereas the upstream area degrades the performance.