Enhanced flow induced vibration piezoelectric energy harvesting performance by optimizing tapered beam

This paper proposes a tapered cantilever beam flow induced vibration piezoelectric energy harvester, for optimizing the tapered beam and improving the output characteristics. The physical model of the tapered beam harvester is conceived, a two-dimensional CFD simulation model is established, and experimental validation as well as investigation is conducted. The output voltage and displacement response of the harvesters with various tapered beams are explored. The results show that the tapered beam possesses more uniform strain distribution and larger equivalent stiffness, and increasing the fixed end width results in enhancing output voltage and reducing vibration displacement. The optimal tapered beam with a tip width of 25 mm and fixed end width of 45 mm is obtained. The maximum output voltages of the tapered beam VIVPEH and GPEH are increased by 58.30% and 33.16% over the rectangular beam, respectively. The vibration displacements of the tapered beam VIVPEH and GPEH are reduced by 18.31% and 25.12% over the rectangular beam, respectively. The tapered effect in the flow field reduces the vortex shedding distance, increases the shedding frequency, enhances the aerodynamic forces, and thus improves the energy harvesting performance. This work lays the important foundation for exploring the cantilever beam flow induced vibration harvester system.