Design And Performance Analysis Of Vortex Vibration Piezoelectric Energy Harvester

In recent years,small wireless sensors and other microelectronic devices continue to develop in all fields have a wide range of applications,but for its energy has been difficult to solve the problem.Most microelectronic devices use traditional chemical batteries,chemical batteries are not easy to replace and the environment caused great harm.Micro-electronic devices can be used in the natural environment,and the natural environment contains rich energy,including mobile energy,solar energy and so on.Among them,the energy collection by the phenomenon of vortex-induced vibration caused by the flow around the bluff body can solve these problems well.Vortex-induced vibration has the characteristics of persistence and excitability,the use of vortex-induced vibration energy collection can be a better solution to difficult to collect energy in low-flow environment,and the vortex-induced vibration in a certain range of flow velocity is relatively stable.Use this feature,energy can be continuously collected.Aiming at the wind energy in the environment,this paper presents a wind energy collector that uses the vortex-induced vibration generated by the flow of air around the blunt body to convert the wind energy into electric energy.First,according to the mechanism of vortex-induced vibration to determine the structure of a small vortex-induced vibration energy harvesting device,also using the method of fluid-structure coupling simulation of the structure simulation analysis,the vibration mode of the small vortex shedding wind collector in the wind is simulated,and it is determined that the collector is indeed vortex induced vibration under the action of the wind.After processing,the data of vibration amplitude and pressure generated by the structure in the vortex-induced vibration mode are obtained,it is found that the vibration amplitude and pressure of the collecting structure increase with the increase of the wind speed and the collection structure radius.When the wind speed is 7m/s,the collection structure with a radius of 0.016m produces a maximum vibration amplitude of 2.526?10^-3m and the maximum pressure is 0.0301Pa.The amplitude data obtained from the fluid-solid coupling simulation is applied as a load to the free end of the PZT piezoelectric ceramic cantilever,and the electromechanical coupling simulation is carried out,the energy conversion process of PZT piezoelectric ceramic cantilever beam is analyzed.When the wind speed is7m/s,the maximum open-circuit output voltage is 3.046V.According to the result of the simulation,the structural parameters of the device were determined,and the experimental test platform was set up according to the simulated environment,the device processing and assembly of the small vortex-induced vibration energy wind collector was completed,and finally,the prototype prototype is developed,small vortex-induced vibration wind energy collector was tested and analyzed through the experimental method,when the wind speed is 7m/s,the voltage can be 2.522V.Because the simulated environment is the ideal environment,and the experimental environment is more complex,it is acceptable to produce a certain error.