Numerical Simulation Of Raft-cultivation Model Under Wave Action

In China, inshore aquaculture, mainly located on protected coastal zones, has grown considerably in the past 20 years to meet the increasing demand for sea food products.With the expansion of the inshore aquaculture industries, the number of suitable near-shore locations becomes limited, and inshore water pollution become more severe. At present, Open Ocean Aquaculture has to be developed to settle the problems which occur in the inshore aquaculture. Growing fish offshore in exposed waters, however, brings a new challenge to the industry. The raft culture facilities need to withstand a high energy environment with a full range of loading conditions such as strong winds, currents and storms. The study of the motion responds of the facilities under wave action should be carried out to settle the technical bottleneck of the development of offshore aquaculture.In this dissertation, based on lumped mass method, Newton's second law and rigid body kinematics, a numerical model is developed. Based on the mumerical model, a computer-simulation system is set up. The dissertation is financially supported by the National Technology Support ProjectThe contents of the dissertation are mainly composed of four chapters. In the first chapter, the anthor gives a general introduction of the relevant knowledge of the raft culture system. In the second chapter, the motion responds of longline raft culture model under the regular wave action are calculated. The impact of longline material and additional weight to the movements of the system are also investigated. In the third chapter, as longline culture system have some weakness, in Norway and other developed countries, longtube raft culture system is becoming more and more popular. In this chapter, the impact of mooring line material and mooring line diameter to the movements of the system and mooring line force under regular wave action are investigated. In the fourth chapter, the motion responds of longtube raft culture model under the random wave action are calculated. Results under the regular wave action and random wave action are compared. At the end of the dissertation, the achievements of my study are summarized.