Design And Experimental Study Of Non-Contact Vortex Induced Piezoelectric Wind Energy Harvester

In order to solve the problem of existing wind energy harvesters in terms of wind speed adaptability,reliability,power generation capacity and cannot meet the need of complex wind field environment sensing monitoring system.A vortex induced non-contact piezoelectric wind energy harvester was presented in this paper.Through the exciter system composed of the elastic beam and the cylindrical blunt body,the piezoelectric transducer in the cylindrical blunt body is indirectly excited to realize the non-contact energy transfer.Its structure and working principle were introduced,and the theoretical and experimental research was carried out.The specific research contents were as follows:1.A two-degree of freedom dynamic model of the piezoelectric harvester was established,and the effects of the proof mass and diameter of the blunt cylinder,the length,width and thickness of the elastic beam,the proof mass of the elastic beam and the proof mass of the piezoelectric transducer on the dynamic response characteristics of the harvester were analyzed.The COMSOL three-dimensional model of the coupler and transducer was established,and the effect of various parameters on the equivalent stiffness and natural frequency of the coupler and transducer was simulated and analyzed,which provided a reference for determining reasonable structural parameters of the coupler and transducer.2.In order to explore the influence of each parameter on the vibration characteristics of the harvester in detail,the fluid-structure coupling finite element simulation model of the wind field environment of the piezoelectric wind harvester was established by COMSOL.The influence of diameter of blunt cylinder,wind speed,length and thickness of elastic beam,and proof mass of elastic beam on eddy field,devortex-induced force,oscillation amplitude and vibration frequency of generator system during vibration of generator system was analyzed by combining Fast Fourier Transform analysis(FFT)and univariate analysis method.3.In order to verify the correctness of the theory and simulation results,a test prototype was designed and made and a test platform was built.The influence rules of the wind speed,the length of the flexible beam,the proof mass of the elastic beam and the proof mass of the piezoelectric transducer on the output voltage characteristics and output power characteristics of the generator were systematically studied.The test results showed that the output voltage and the effective frequency band of the generator can be effectively adjusted by changing the wind speed,the length of the flexible beam,the proof mass of the elastic beam and the proof mass of the piezoelectric transducer.When the wind speed was 32 m/s,the load resistance was 100 kΩ,the maximum output power of external piezoelectric transducer was 0.215 m W.When the wind speed was 32 m/s,the load resistance was 550kΩ,the maximum output power of internal piezoelectric transducer was 0.094 m W.