Study On Underwater Piezoelectric Energy Harvesting Based On Wake Galloping

Piezoelectric energy capture has the advantages of simple captive energy principle,light and low noise,wide application,and environmental protection.It can effectively solve a series of problems such as environmental pollution and greenhouse effect caused by battery storage and power supply,and has a good development prospect.In this paper,by studying the trapping characteristics and laws of piezoelectric traps under the action of wake,an underwater piezoelectric energy harvester with high efficiency,wide frequency band and easy fabrication is developed which can be obtained from the environment.Energy to power the microelectronic devices.Firstly,based on multidisciplinary theory such as material mechanics,mechanical vibration and piezoelectric,this paper establishes a mathematical model of underwater piezoelectric energy harvester(PEH)based on wake excitation,and proposes flow-solid-electric multiphysics.Field coupling equations,using theoretical derivation and parameter identification to obtain various parameters of the energy harvester,provide parameter support for the simulation analysis of the energy harvester.Secondly,the simulation analysis of the tandem-excited serial piezoelectric energy harvester is carried out,revealing the diameter of the spoiler,the diameter of the response cylinder,the center distance of the bluff cylinder and the response cylinder,and the flow rate to the capture energy of the trap.In this paper,the diameter D of the bluff cylinder is 5-25 mm,the diameter d of the response cylinder is 15-20 mm,the center distance between the bluff cylinder and the response cylinder L is 2D-6D,and the velocity v is 0.1-0.6m/s.The relationship of characteristics.When the diameter of the bluff cylinder and the response cylinder are constant,as the center distance increases,the vortex-induced vibration and the wake excitation response of the vibrator are both advanced,and the response strength is weakened.When the diameter of the response cylinder and the center distance are constant,as the diameter of the spoiler increases from 5 mm to 25 mm,the vortex-induced vibration response gradually lags,the peak of the vortex-induced vibration gradually increases,and the wake-vibration stability value gradually decreases.When the center distance and the diameter of the bluff cylinder are constant,as the diameter of the response cylinder increases,the vortex-induced vibration response advances and the wake excitation response increases.When the diameter of the bluff cylinder is smaller,the vibration frequency of the vibrator is near the vortex induced vibration frequency of the single vibrator.As the diameter of the bluff cylinder increases,when the vortex shedding frequency is lower than the vortex-induced vibration frequency of the single vibrator,the vibrator frequency is near the vortex shedding frequency,and when the vortex shedding frequency is higher than the vortex-induced vibration frequency of the single vibrator,the frequency of the vibrator is stable near the natural frequency of the vibrator.Through data comparison,the PEH-05-15-2D capture energy enhancement rate is the best.Compared with PEH-00-15,the VRMSmax increase rate reaches 102.9%,and the energy density increase rate reaches 269.93%.PEH-05-20-2D The capture energy performance is optimal,the VRMSmax reaches 43.72 V,and the energy density reaches 2.327J/m3.Finally,a prototype of underwater traps based on wake excitation was developed,and an open channel experimental platform was built.The correctness of the above mathematical modeling and simulation was verified by a series of captive experiments.