Study On The Hydrodynamic Characteristics Of Floating Point Absorbers Under The Optimal Energy Absorption Conditions

With the rapid development of the world economy,the consumption of global resources is increasing,but the total reserves of fossil energy,which is not renewable,are limited?Therefore,the task of finding new energy is extremely urgent,and the development and utilization of renewable energy sources have become a global consensus?wave energy as a kind of clean and pollution-free renewable energy has a good development prospect?Therefore,various types of wave-energy converter have been gradually developed,among which point absorb wave energy converter have been favored by scholars of wave energy due to their small size and high energy absorption efficiency?In this paper,the hydrodynamic characteristics of a point absorber floating body are studied systematically ? Meanwhile,AQWA is used to calculate the hydrodynamic characteristics and MATLAB is used to draw a spectrum that can be used for design for the corresponding research parameters,and the variation law of hydrodynamic characteristics of floating body is analyzed under the different parameters?Firstly,the distribution of wave energy resources in the world,the classification of wave energy converter and the research status of point absorber wave energy converter are described systematically?The basic equations and boundary conditions of the floating body moving in waves are analyzed and the solution process of the energy absorption characteristics of the floating body and the oscillation stroke are described?Secondly,the hydrodynamic characteristics of a floating body with heave motion are analyzed with the variation law of the diameter of the floating body and the draft of the cylinder?The resonant frequencies that coupling through floating's natural frequency and wave frequency are obtained by interpolation,and the resonance period spectrum is drawn after dimensionless and the resonance period formula is fitted?Based on the resonance frequency,the relative bandwidth and oscillation stroke of the floating body are drawn and analyzed?Some conclusions about the heave motion of floating body are obtained through analysis?Then,the hydrodynamic characteristics of the floating body in composite motion are analyzed?At the same time,the PTO damping and output power of the floating body are analyzed based on the resonance frequency,and it is concluded that the output power of each mode of the composite motion is less than that of the single-degree-of freedom motion,but the total output power is larger?In addition,the design parameters of the floating body are analyzed and provides the data of sway stiffness for the floating body to realize composite motion?Finally,the composite motion characteristics of the floating body with heave damping equal to the sway damping are discussed,which can provide some reference for the design of the point-absorbing wave energy converter in the future?Finally,the array spacing of the floating body with heave motion is studied?By changing the vertical and horizontal spacing,the output power ratio between array single floating body and without array single floating body was analyzed,and then the optimal spacing that satisfaction the individual optimal energy absorption state was obtained?In addition,the trajectory of the floating body with composite motion is analyzed according to the oscillation stroke and the phase Angle,and the optimal trajectory of the floating body with the best energy absorption state is obtained.