| With the global shortage of fossil energy and the increasingly serious problem of environmental pollution,the development and utilization of renewable energy has increasingly become a research hotspot.With the ocean,wave energy is distributed all over the world,and its reserves are very huge.The development and utilization of wave energy can effectively solve related problems.In the process of studying the energy efficiency of the wave energy device,the hydrodynamic characteristics and energy conversion characteristics of the device should be analyzed.Although the related research has been going on for many years,there are still many problems.There are many kinds of wave energy devices.This paper selects the typical oscillating float wave energy conversion device as the research object,and establishes the corresponding vibration model based on the motion process of the floating body with the wave on the basis of potential flow theory and vibration theory.through the method of numerical analysis and graphic data analysis,the hydrodynamic and energy conversion characteristics of floating body under the action of waves are deeply discussed,and its changing rules are studied.According to oscillating float wave energy device,based on the previous studies on float hydrodynamics and energy conversion at home and abroad,the wave energy device is divided into single type,two-body type with damping plate and two-body array type in this paper.the corresponding vibration models are established respectively,and the energy conversion mechanisms of different types of wave energy devices are expounded based on the vibration theory of single degree of freedom and multi-degree of freedom.Based on the linear potential flow theory,the analytical expressions of optimal energy capture for single-body and doublebody wave energy devices are derived.According to single oscillating float wave energy device,the float is connected to the fixed base through the energy conversion(Power Take-off,PTO)device.Based on the linear wave hydrodynamic theory and the classical analytical method of boundary matching expanded by eigenfunction,the floats with four axisymmetric configurations of concave,conical,paraboloid and ellipsoid are studied.The wave excitation force,radiation force,vertical response amplitude and capture width ratio are calculated and studied respectively.At the same depth,the influence rules of four configurations of floats are compared and studied from two aspects of fixed draught ratio and fixed frequency.According to catamaran oscillating float wave energy device with damping plate,based on the potential flow theory and vibration theory,the radiation and diffraction of double floating body are studied by using the semi-analytical method of boundary matching with eigenfunction expansion.furthermore,the wave excitation force and radiation force acting on the float and the damping plate can be obtained by using the Bernoulli equation.After that,the hydrodynamic characteristics and wave energy conversion characteristics of the double floating body device with damping plate are studied from the point of view of the radius and immersion depth of the damping plate,and the influence of the opening size of the damping plate on the device with perforated damping plate is deeply studied.According to array wave energy device,based on the panel method of linear wave hydrodynamic theory,the coupling hydrodynamic coefficient of double floating body array and wave action is obtained.Combined with multi-degree-of-freedom vibration theory and optimization method,the optimal PTO damping coefficient of double floating body array is obtained.On this basis,the array influence factor is introduced,and the energy conversion characteristics of linear and triangular double floating body array are studied deeply.This paper focuses on the effects of different wave angles,float spacing and array layout on the wave energy conversion of double floating body array devices and the causes of interference. |
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