Research On Broadband Piezoelectric Energy Harvesting System Based On Acoustic Black Hole Effect

The Acoustic Black Hole(ABH)effect is a phenomenon in which the thickness of the beam or thin plate structure is tailored according to the law of power change,so that the bending wave at the tip of the structure is reduced to zero without reflection,so that the energy can be achieved at the end of the structure.Gathering and efficient recycling.In view of the unclear generation mechanism of periodic acoustic black hole broadband energy recovery,and the uncertainty of the influence of various structural parameters on the output characteristics of the system,this paper proposes a broadband piezoelectric energy recovery system based on periodic acoustic black holes and establishes it based on the Gaussian expansion method.The semi-analytical model of acoustic black hole piezoelectric energy capture coupled with piezoelectric layer,combined with energy band theory in the frequency domain,analyzes the influence of structural parameters on the output characteristics of the energy recovery system,and finally verifies periodic acoustic black holes through piezoelectric energy recovery experiments For the effectiveness of broadband recovery of energy.The research content of this article mainly includes:(1)The deduction of geometric acoustics theory and limited modeling analysis verify the energy accumulation effect of the acoustic black hole structure;and establish an energy recovery system based on the acoustic black hole structure to compare the acoustic black hole beam and the uniform beam in terms of energy recovery power and energy recovery efficiency The energy recovery effect of the acoustic black hole verifies the effectiveness of the acoustic black hole structure for optimizing the energy recovery effect.(2)For the acoustic black hole energy recovery system coupled with the piezoelectric layer,a semi-analytical analysis model based on Gaussian function is established;through comparison with the calculation results of finite element,the effectiveness of the model is verified from the two aspects of modal response and frequency domain response,and Through the speed comparison of the two calculation methods,the superiority of the rapid solution of the semi-analytical model is demonstrated.(3)Based on the energy band theory,the energy band structure of the periodic acoustic black hole is deduced,combined with modal analysis,the passband frequency range in the energy band structure is determined;and the comparative analysis of the energy band structure and the output characteristic curve shows that the structure of the periodic acoustic black hole is generated by The frequency pass band realizes the mechanism of broadband energy recovery.(4)Taking the key structural parameters of the periodic acoustic black hole as the research object,it explores the change law of the energy recovery system’s output characteristics and energy band structure under different structural parameter conditions.The research results show that each structural parameter will affect the output characteristics of the system by affecting the frequency range of the passband and the energy concentration effect,revealing the regulation mechanism of achieving energy broadband recovery through parameter design.(5)The piezoelectric energy recovery experimental platform was built to conduct energy recovery comparative experiments on periodic acoustic black hole beams and uniform beams.The experimental results show that the periodic structure has a multipeak and high-amplitude energy recovery effect in the passband range,which verifies the periodic acoustic black hole The effectiveness of the structure’s broadband energy recovery characteristics.