Numerical Simularimental Exploration Of Vortex-induced Piezoelectric Energy Collection Structures

With the rapid development of science and technology,the international on the earth's environmental protection consciousness gradually strengthened,human exploration of new energy have further in-depth study,by collecting the environment of the small energy supply for small devices has become the new energy research hot spot.The oceans and rivers in the fluid flow around a blunt body formation of vortex induced vibration is a common phenomenon in nature,vortex induced vibration phenomena in the velocity is low?<1 m/s?of the cases occur,and when to take off the vortex frequency of fluid and structure,the natural frequency will produce stable and continuous harmonic vibration,is the bottom of the sea,such as low flow velocity one can collect energy in underwater environment,In recent years,it has attracted the attention of academic circles.In this paper,the vorticity induced vibration of a flexible circular tube with a built-in piezoelectric cantilever is studied in low-velocity underwater environment to provide a continuous,stable and environmentally friendly energy for the nodes of the underwater wireless sensor network.Firstly,this paper introduces the micro-energy technology,the acquisition of micro-energy and the research status and existing problems of micro-energy collection structure at home and abroad.The research status of vortex-induced vibration piezoelectric energy collection technology is emphatically analyzed,and the research direction of this paper is proposed.Secondly,the relevant mechanism of vortex-induced vibration is studied,the influence of parameters such as Re and St on vortex-induced vibration is analyzed,the dynamic equation of fluid-solid coupling is given,and the numerical simulation algorithm of fluid-solid coupling under immersion boundary is studied.Then with the vortex induced vibration of flexible pipe in the numerical simulation of the model by setting the initial conditions and the basic parameters of three-dimensional fluid-structure coupling numerical model is established,the numerical simulation results show that the resistance of fluid and the vibration of the flexible pipe structure rigidity condition than single flexible pipe and double flexible pipe is stable,and the vibration amplitude is bigger,the velocity of 1.1 m/s,pipe diameter is 0.02 m,height of 0.08 m,and the resistance of fluid under the condition of distance of 0.06 m,flexible pipe vibration amplitude can reach 5x10^-4 m,of the array of all the vibration response of the flexible pipe is bigger than the front results,And the second flexible round pipe after the rigid resistance fluid has a stable and continuous vibration response,under the same conditions,its vibration amplitude is 2.3x10^-3m.The piezoelectric coupling numerical simulation was carried out on the piezoelectric cantilever beam by taking the vibration displacement of the top of the circular tube as the initial condition,and the influence of the distance between the flexible circular tube and the bluff body,the height of the circular tube and the velocity of the flow on the output voltage of the piezoelectric cantilever beam was analyzed.Under the optimal vibration condition,the maximum open circuit output voltage of the flexible circular tube was 55.7v.Finally,the piezoelectric energy collector of vortex-induced vibration was fabricated and the device was fabricated and sealed.The experimental system is designed,the experimental platform of vortex-induced vibration piezoelectric energy collection is constructed,and the performance test and analysis of piezoelectric energy collection structure are completed.The average voltage value of the energy collection structure was 294mV at a flow rate of 0.5m/s,a radius of 0.01m and a height of 0.08m.Through the analysis of the simulation and experimental test results,it is concluded that the minimum starting velocity of the vortex-induced vibration energy collector is 0.65m/s.The theoretical analysis,numerical simulation and experimental study of vortex-induced vibration piezoelectric energy collection technology are carried out in this paper,which provides a reference for the actual preparation and testing of vortex-induced vibration piezoelectric energy collector,and is of great significance for the development of underwater wireless sensor network and the progress of renewable energy technology.