Simulation Analysis Of Piezoelectric Power System Driven By Oscillating Water Column

Ocean energy is the most widely distributed renewable energy and wave energy is its most commonly available form of energy.At present,the most widely used wave energy conversion device is oscillating water column(OWC)wave energy converter.It is of great significance to study the gas chamber structure and power generation mode of oscillating water column wave energy conversion device to improve the conversion efficiency of wave energy.In this paper,a new oscillating water column wave energy conversion device was established by oscillating the water column gas chamber and the piezoelectric plate,and the wave energy collection in the oscillating water column gas tank and the circular piezoelectric structure were studied respectively.The linear wave theory combined with computational fluid dynamic analysis(CFD)was used to simulate wave-making and wave-elimination.ICEM CFD software was used to combination of structured grid and unstructured grid to divide the model of the gas chamber.With the VOF model of FLUENT software and the phase-separated fluid simulation technology are used to track and measure the hydrodynamic characteristics of gas chamber flume.Based on the piezoelectric constitutive equations,the piezo-electric boundary conditions are selected according to the constraint of the piezo-plates and the four types of piezo-electric equations Equation,APDL custom instructions function to write the model and meshing instructions,select the piezoelectric material model for piezoelectric coupling simulation,in the center and bottom of the fixed circular piezoelectric plate edge were concentrated and variable loading pressure applied to study the piezoelectric power generation characteristics.In the three-dimensional simulation,an oscillating water column wave power generation device based on piezoelectric effect was designed by combining the oscillating water column chamber and the circular piezoelectric plate.FLUENT and APDL are respectively used to optimize the piezoelectric plate structure and the structure of wave-guiding structure at the bottom of gas chamber to obtain the optimal structure model.Fits the pressure of the chamber converted by the collected wave energy and applied to the bottom surface of the piezoelectric piezo piezoelectric coupling to obtain the structural optimization of the piezoelectric chamber water tank model to discuss the power generation law.The results show that the oscillating water column gas chamber is easier to get resonance due to less influence of the wave reflected from the wall in the early stage and its conversion efficiency is higher;The gas pressure in the gas chamber fluctuates with the ups and downs of the wave;Piezoelectric center force than the bottom force can produce higher voltage and deformation,deformation is proportional to the amount of voltage;the bottom of the wave structure is circular OWC gas chamber with better hydrodynamic performance and wave energy conversion efficiency;The center of the hole is 0.01m thickness of 0.0001 m piezoelectric film produced deformation and voltage is better than other size parameters of the piezoelectric film;Based on the piezoelectric effect of the gas chamber sink power generation device has a more efficient wave energy conversion,the deformation of the piezoelectric film changes sinusoidally with the gas pressure in the gas chamber,and the voltage changes sinusoidally with the change of the deformation amount,the voltage direction and the deformation direction are opposite.