Energy harvesting utilizing reciprocating flow-induced torsional vibration on a T-shaped cantilever beam

Abstract

This paper proposes a T-shaped cantilever energy harvester powered by flow-induced torsional vibration. To collect and convert the mechanical (kinetic) energy into electric power, a pair of symmetrical acrylic cylindrical bluff bodies were installed onto the bottom surface of the T-shaped cantilever beam, one at each end; There is also one patch of Macro Fiber Composite (MFC) used as an energy collector and converter which was attached to the fixed end of the cantilever beam. This proposed setup of the energy harvester is able to generate sustainable electric power by harvesting natural mechanical power resulted from the torsional vibration of the beam due to fluid's vortex shedding effects. The proposed energy harvester has the novelty in that our approach harvests fluid flow's energy in a reciprocal fashion making full use of renewable energy incurred in areas surrounding the two bluff bodies. Both the theoretical and experimental analyses on the proposed energy harvesting structure were performed and demonstrated in this paper. The case in the test rig we studied on the proposed energy harvester was able to generate sustainable electric power of approximately 1.0 µW when flow speed was measured to be 0.33 m/s flowing through two bluff bodies each of 29.5 mm diameter. This work also looks into and discusses pros and cons of various scenarios in terms of structural geometric variations for system optimization of the proposed energy harvester.