Energy harvesting and energy conversion in an electromechanical coupling acoustic black hole beam

Abstract

Acoustic black hole (ABH) shows unique and attractive features of energy focusing when the flexural wave propagates along a structure with a variable power-law thickness profile, which are found to be conducive to effective energy harvesting. In this paper, an improved electromechanical ABH model is established based on Timoshenko beam theory, which considers the high-frequency shear and rotational effects of the beam, as well as its coupling with PZT coating and other additional elements like damping layers. External electrical modules including both linear and nonlinear circuits can also be easily integrated into the system to form a fully coupled electromechanical model. The proposed model is then used to analyze typical ABH-specific features such as energy focusing and energy harvesting. Numerical results demonstrate the excellent energy harvesting performance and confirm that installing PZT on the ABH beam warrants higher electrical power than the uniform beam. Moreover, studies explore the relationship between the electromechanical coupling and the energy harvesting efficiency, and different methods to enhance the electromechanical coupling are also investigated. Finally, experimental results are presented to demonstrate the feasibility of ABH beam in energy harvesting.