Analysis Of Multi-body Coupling And Power Generation Performance Of Truss Wave Energy Power Plant

Due to problems such as environmental pollution and energy shortages,the development and utilization of renewable energy has been paid more and more attention by more and more countries.Wave energy has received widespread attention due to its wide distribution,large reserves,renewable,non-polluting and other advantages.Among them,multi-floating wave energy converters based on floating or semi-submersible platforms are an important development direction for wave energy utilization.However,there are few researches on multi-floating wave energy power generation devices,and most of them are based on potential flow.The theoretical study did not consider the effect of stickiness.In this paper,based on the Reynolds average Navier-Stokes equation,a viscous three-dimensional numerical wave pool is established,and the K-Epsilon double-layer turbulence model is used to the hydrodynamic performance and absorbed power of a multi float wave energy generator coupled with a truss platform in different waves are studied.In this paper,the convergence of grid scale and time step of viscous three-dimensional numerical wave tank is studied firstly,then a series of physical model tests are carried out,and compared with numerical simulation,the results verify that the three-dimensional numerical wave tank has good stability and accuracy.In this paper,STAR-CCM + software is used to simulate the influence of octagonal truss platform with different degrees of freedom on wave surface and the heave effect of octagonal floats.It is found that the octagonal truss platform has different influence on the centroid position of the float with different angles to the incident wave,including the wave breaking phenomenon and the first-order change of the wave surface lifting,and the wave breaking phenomenon will be alleviated with the increase of the degree of freedom of the platform.Then,the hydrodynamic performance of single floater without damping and eight floater coupled with octagonal truss platform with different degrees of freedom in different sea conditions is studied.It is found that for a single float,the force and motion of the float in different directions tend to be the same under different sea conditions.For the coupling of the eight floats and the platform,the force and motion trend of the eight floats under different sea conditions tend to be consistent with the increase of the degree of freedom of the platform.Finally,this paper studies the corresponding damping coefficients of the buoy in the South China Sea,and calculates the power generation efficiency and hydrodynamic performance of single buoy and octagonal truss platform with multi-body coupling under different degrees of freedom.It is found that for the sea conditions studied in this paper,the power generation and efficiency of the isolated buoy in small wave period are better,and the power generation performance of the buoy in back wave direction is better than that in head wave direction;For the eight floaters coupled with truss platform with different degrees of freedom,when the platform only heaves,the total power generation is the largest and the power generation efficiency is the highest,and the smaller the period is,the better the power generation performance is.The research results in this paper have a good reference value for the simulation and analysis of the power generation and efficiency of the multi-float coupled with octagonal truss platform and the hydrodynamic performance.