Analysis And Experimental Study On Wave Energy Generation Of Floating Oscillating Water Column Based On Dielectric Elastomer

The traditional ocean buoys are powered by batteries,and a few number of them are powered by solar energy and wind energy.The instability of the marine environment leads to the failure of the device to provide long-term and stable power supply.Today,the oscillating water column wave energy generation device is turbine power generation.Turbine installation is mostly metal structure,in the marine wet environment,the service life is greatly shortened.In this paper,a model of floating oscillatory hydro-column generator based on dielectric elastomer is proposed.The wave energy acquisition device is a floating body,which can be put into the ocean and near the shore,and the environment adaptability is strong.Power generation device is dielectric elastomer film,can withstand large deformation,strong impact resistance,can adapt to harsh marine environment.Based on the micro-vibration amplitude wave theory,the relative pressure at the bottom of the water column is solved,and the stress on the water column is analyzed.The motion equation of the water column under the action of the relative pressure,the relative pressure of the gas chamber,the gravity of the water column and the linear hydraulic loss is solved.The motion equation of floating body under the action of wave force,damping force,relative pressure of gas chamber and self-gravity is solved by analyzing the force of floating body.Based on the Froude-Clayoff hypothesis theory,the wave force of floating body with different wave parameters,the radiative damping of floating body motion and the additional mass of floating body are obtained by simulation and analysis of three kinds of floating body models based on diffractive theory.The Simulink motion model of water column and floating body is established and the relative displacement between water column and floating body is analyzed under different parameters.The relative displacement between the water column and the floating body and the volume change of the gas chamber under the action of thin film deformation and the relative displacement between the water column and the floating body are calculated.The air chamber radius r=0.1m,the air chamber height ha=0.3m,Co=147 Pa·(m3)1.4,the relative displacement of the water column and the floating body and the volume change of the air chamber under the action of the film deformation are solved.According to the gas equation of state,the relative pressure of the gas chamber is solved,which drives the film deformation.The joint equation of the gas chamber pressure and the top displacement of the film is established,and the relationship between the pressure of the gas chamber,the displacement of the top of the film and the wave parameters is obtained.A uniform deformation model of dielectric elastomer film is established,and the dielectric elastomer is equivalent to a parallel plate capacitor.In this paper,a constant charge cyclic generation method is used to solve the capacitance size in the original and deformed states of the film.The generation capacity of single stretch dielectric elastomer film is solved and the influence of film parameters on the generation capacity is analyzed.The optimal film parameters are selected,when the pre-drawing radius of the film is r0=6 cm and the thickness of the film is?0=0.1m,the effect of the thin-film generation is the best.The wave energy in a wave cycle and the power generation of three device models are analyzed under different wave parameters,and the energy conversion efficiency of the three devices under different wave parameters is solved.The results show that the wave energy conversion efficiency of disk device is 0.51%,that of conical floating body is 0.63%,and that of cylindrical floating body is 1.2%when the wave height H=0.3 m and the period of T=6 s.And provides a theoretical basis for long-acting stable power supply of the pelagic buoy device.The experimental platform of dielectric elastomer driven by pressure is set up.The displacement of piston replaces the relative displacement of water column and floating body.The displacement of the top of dielectric elastomer film,the pressure of air chamber and the output voltage under different displacement of piston are analyzed.It provides the experimental basis for the floating oscillatory hydro-column generator based on dielectric elastomers.