Numerical Simulation Of Hydrodynamic Response Of Gravity Cage

Gravity cage is now widely used in deep sea aquaculture cage,the study of its hydrodynamic performance and motion response,is the necessary basic work to solve the design,layout and maintenance of the cage,but also conducive to the selection of cage installation area,as far as possible to reduce the influence of the cage by the force of wave flow.Existing research is mainly focused on the single forward hydrodynamic performance,so in this paper,based on the focus quality standard and principle of rigid body kinematics,the gravity cages numerical model was established,the model with physical model test,the monomer cages in wave,flow and wave flow coupled environmental factors affect water dynamic response characteristics,Then the hydrodynamic response characteristics of the double body cage under the influence of wave and flow are studied.This paper mainly involves the following aspects:(1)Based on the lumped mass method,mesh group method and Morison theory,a numerical model of gravity cage was established,and the results of Kristiansen test and Cristian numerical simulation were combined to verify the deformation shape of mesh clothing,resistance performance and calculation results of real scale model.The reliability of the numerical model is confirmed.(2)Using numerical simulation method to study the single cage under the combined action of pure current,pure wave and wave current,and analyze the deformation degree of the net coat,the motion response of the floating frame system and the force of the mooring system;To study the influence of different current and wave directions on mooring cables;By changing the weight of the sinker and the velocity,the deformation degree of the mesh garment is analyzed by using the nine-point spatial coordinate method.(3)Based on the study of the hydrodynamic response characteristics of the single cage,the dynamic response performance of the two-body cage under wave and flow conditions was studied,and the influence relationship of different wave and flow conditions on the effective tension of each mooring cable was obtained.In conclusion,the purpose of this article is to analyze gravity cages under wave loading dynamic response performance of water,through the numerical simulation method to study the net body deformation of the monomer cages,floating movement and mooring cable force,hydrodynamic performance of twin area is analyzed,through the real scale model validation,has certain practical significance to make numerical simulation,According to the dynamic response characteristics of gravity cage under different wave and flow conditions,the wave and flow conditions which have the greatest and the least influence on gravity cage are found out,and reasonable suggestions are provided for choosing the appropriate sea area for placing the cage.