| Nowadays,mariculture accounts for more than half of global aquaculture production,and the vast ocean contains infinite potential.As a result of human life production activities,leading to serious damage to the coastal environment,shallow sea farming is facing a series of problems such as diseases and pollution.The traditional coastal aquaculture and fishing have been unable to meet the growing material needs of mankind,to this end,mariculture to the far-reaching sea has become an inevitable choice.As one of the three main ways of mariculture,raft farming has gradually evolved from the traditional bamboo raft structure to the offshore combination forms.Offshore harsh environment makes a serious challenge to the design of the offshore raft structure,therefore it is urgent to study the hydrodynamic characteristics of the offshore shellfish raft structure.This paper can be divided into two parts: One of the two kinds of common hatching methods(sling farming and cage culture)for raft breeding facilities to carry out physical model test,to explore their hydrodynamic characteristics,for the maintenance of numerical modeling and engineering design to provide experimental support;The numerical simulation of the two-point anchored raft structure is carried out.Based on the concentrated mass method and the rigid body kinematics principle,the numerical model of the offshore shellfish raft breeding facility is established with the modified Morison equation.The fourth order RungeKutta method is used to numerically solve the equations of motion to obtain the dynamic characteristics of offshore shellfish raft farming facilities under waves and currents load.This paper is divided into six chapters: The first chapter introduces the research background of this paper,analyzes the research status and progress of the domestic and foreign scholars in raft farming field,and builds the research goal and content on this basis.The second chapter is the introduction of the basic theory and the numerical model,and analyzes the force and motion of the three components of the two-point anchored raft farming facility.In the third chapter,the hydrodynamic characteristics of the shell roughness under wave and water flow are studied experimentally,and the hydrodynamic coefficients of the surface roughness cylinders are analyzed.In the fourth chapter,the hydrodynamic characteristics of lantern net under the action of regular wave and uniform flow are discussed respectively by means of model experiment,and the influence of shellfish culture density on cage force is analyzed.The fifth chapter is to simulate the hydrodynamic characteristics of single raft structure,and analyze the dynamic response under the action of regular wave and irregular wave.Chapter 6 analyzes the hydrodynamic characteristics of different combinations of floating raft structures under the influence of regular wave,uniform flow and wave combination.Finally,the research results of the full text are summarized and suggestions are given for future research work. |
