Design And Simulation Of A Segmented Piezoelectric Energy Harvester Based On Vortex-induced Vibration In Water

To detect the complex marine environment,a variety of low-power sensors are usually placed in the ocean.Most of the marine sensors are powered by traditional chemical batteries,which have disadvantages such as poor power supply permanence,poor environmental cleanliness and large size.The marine environment is different from the terrestrial environment and the sensors are not easily recyclable.Therefore,a new type of power supply device that can be used to supply power for marine low-power sensors has become the focus of research by domestic and foreign scholars in recent years.The ocean,like air,contains enormous vibrational energy.Among them,the Karman vortex effect in the ocean as a regular known vibration method,it can make the piezoelectric material vibrate and generate energy.At the same time,piezoelectric vibration energy harvesting has a broad development prospect as a durable,clean and pollution-free technology for power supply.This paper firstly has analysed the research background of piezoelectric energy harvesting,the current situation of domestic and foreign research,and the development and research status of vortex-induced vibration theory,especially the current situation of domestic and foreign research of vortex-induced vibration energy harvesting.A segmented piezoelectric energy harvester has been proposed according to the Karman vortex street theory on the basis of summarizing the advantages and disadvantages of domestic and foreign scholars' research.Secondly,the piezoelectric effects and the basic parameters of piezoelectric materials have been introduced.And four piezoelectric equations related to the forward and inverse piezoelectric effects have been described to provide a theoretical basis for the simulation of the piezoelectric vibrator.According to the piezoelectric theory,the cantilever beam type single-layer piezoelectric oscillator model and equivalent circuit model have been established.The relationship between the thickness of the piezoelectric cantilever beam substrate and the output voltage and output power of the piezoelectric oscillator have been analyzed.The relationship between the external load and the output power has been analyzed.Then,the governing equations of fluid mechanics and the dimensionless numbers related to the flow around a cylinder have been builded.The computational fluid dynamics of fluids,as well as discrete equations and turbulence models have been briefly described.On this basis,the modeling and simulation of the flow around the cylinder have been carried out,and the simulation results have been compared and analyzed with the research results of previous scholars.Finally,the flow-structure interaction theory and dynamic meshing theory have been analysed.The flexible plate under the action of the Karman vortex street has been modeled and simulated,and the average lift coefficient of the flexible plate has been analyzed.Then the piezoelectric vibrator under the action of the Karman vortex street has been modeled and simulated.The output voltage of the piezoelectric vibrator trending with different lengths have been obtained.The output power with the length of the piezoelectric vibrator and the external load have been gotten.The deflection of piezoelectric vibrator at different lengths and moments have been drawn.According to the deflection curve,the piezoelectric oscillator has been segmented.The output voltage and power with different lengths of the piezoelectric oscillator and the external load have been studied.The similarities and differences with the unsegmented piezoelectric oscillator data have been analyzed,and the conclusions of this paper have been drawn.