Performance investigation of a crossing angle adjustable galloping-based energy harvester

In this study, we proposed a crossing angle adjustable galloping-based piezoelectric energy harvester (CAGPEH) configured with a lambda-shaped beam to improve the energetic performance. The proposed structure can overcome the limitation of the installation capability of a conventional galloping energy harvester with a single cantilever beam by varying the crossing angle. This structure can change the crossing angle between primary and secondary beams so that the bluff body always faces the changing wind direction to ensure an efficient harvesting performance. A distributed parameter model was established using Euler-Bernoulli beam theory and Lagrange method, and a series of numerical analyses was performed to uncover the dynamical behaviors of the aero-electromechanical coupled system. The first two modes were considered to obtain a comprehensive understanding of the dynamic behaviors at different crossing angles. We validated the theoretical model through amplitude and output voltage comparisons between numerical and experimental results. The results show that a larger crossing angle and a smaller length proportional factor of the primary and secondary beams help reduce the critical wind velocity. The results show that a significant increase rate of 103% in the overall average output power (OAOP) can be achieved with a crossing angle of 30° and a proportional factor of 0.6. It is expected that the CAGPEH can help develop self-power systems for applications in wireless sensor systems.