Study On Energy Harvesting System Using Marine Animal As Carrier

With the application and development of real-time marine environment monitoring technology based on marine animals,the problem of energy supply of the monitoring system is becoming increasingly severe.The locomotion flexibility of marine animals makes battery replacement costly and difficult to achieve.By harvesting energy from the surrounding environment,it is hoped that the limitations imposed by batteries on the development of marine environmental monitoring technology can be removed.Piezoelectric energy harvesting has become the main way to convert mechanical energy into electrical energy in energy harvesting systems due to its advantages of structural simplicity,high power density,and design flexibility.This paper carried out research on the energy harvesting system with marine animals as the carrier,explored the basic theory of the cantilever beam structure based on vortex-induced actuation and the ring structure energy harvesting system based on the swimming characteristics of marine animals,analyzed the power generation performance of the two structural forms of energy harvesting system by combining mathematical model and finite element simulation.Aiming at the piezoelectric cantilever beam energy harvesting system of vortex-induced vibration,a dynamic model of vortex-induced vibration water flow energy harvesting is established.Using the fluid simulation software FLUENT to simulate and analyze the two-dimensional simplified model,the influence of factors such as flow velocity and blunt body size on the flow field around the structure is studied,and the fluid force at the boundary of the blunt body under different working conditions is obtained,providing data to support the numerical solution of the system.It is found that,the vortex shedding frequency decreases with the increase of the diameter of the bluff body for a constant flow velocity and the vortex shedding frequency increases with the increase of the flow velocity for a constant bluff body size.The numerical solution results show that compared to high flow rates,the system has weak vibration amplitude,low output voltage and poor energy capture at low flow rates.Aiming at the annular piezoelectric energy harvesting system of marine animal swimming characteristics,the dynamic model of the system is established.With the aid of polynomial fitting of the nonlinear stiffness of thin-walled circular ring,the dynamic equations of the system is solved by numerical iteration method,and the influence of the geometric parameters of the ring structure on the output displacement characteristics is analyzed.The size of the annular piezoelectric energy harvesting structure is determined by optimizing the structural parameters with the objective of maximum relative output displacement under a set system excitation.Preliminary results show that the maximum output power of 617.24 is obtained at a load resistance of 9.1kΩ.The feasibility of the ring piezoelectric energy harvesting device is confirmed by the experimental research on the power generation performance of the ring piezoelectric energy harvester.