网衣和网箱对波浪传播的影响及其水动力特性

发布时间：2018-04-22 23:32

本文选题：三维数值波浪水槽 + 网衣　；参考：《大连理工大学》2014年硕士论文

【摘要】：近年来,随着人类对海洋渔业产品需求量日渐增多,野生海生物被过度捕捞。同时,高速的经济发展而带来的近海工业污染,使得近海水域生态环境逐渐恶化。需求量的增大以及生存环境的恶化,使得渔业资源几近枯竭,市场供不应求。为解决上述问题,深海网箱养殖近年来发展迅速。相比近海养殖,深海养殖意味更强的风浪和水流条件,网箱在此恶劣坏境下极易破坏,同时网箱内水流和波浪等养殖环境也和鱼类生长息息相关。渔网作为水产养殖网箱的重要组成部分,是一种复杂的柔性结构物,以其作为主体进行相关波浪的研究非常少。针对以上情况,我们首先进行了物理模型试验和相应数值模拟,研究了网衣对波浪传播的影响,找出网衣与波浪相互作用机理及规律；在此基础上进一步研究了波浪与网箱的水动力特性和网箱对波浪传播的影响。本文将CFD软件FLUENT应用于数值模拟,采用多孔介质模型模拟网衣,建立了模拟网衣与波浪相互作用的三维数值波浪水槽模型。基于该数值模型研究了波浪经过网衣作用后波高衰减的变化规律,并与物理模型试验结果进行比较。通过对比数值模拟和物理模型试验的结果,证明了该三维数值模型模拟网衣对波浪传播影响的可行性。论文内容包含五章：第一章绪论,简要介绍了课题研究背景、目的及有关其国内外研究进展。第二章介绍了数值模型的相关数学方法,包括控制方程、多孔介质模型与网衣的相互转化、三维数值波浪水槽的建立及其网格的划分、数值波浪水槽造波和消波的数学原理。第三章首先验证了数值波浪水槽造波消波的有效性,接着通过数值模型模拟了网衣周围的波浪场,并对其进行了相关物理模型试验验证,初步了解了网衣与波浪作用机理,得出了网衣对波浪传播影响规律。第四章研究了不同入水深度的网片组合对波浪传播带来的影响以及改变网片个数对周围波浪场的影响。第五章根据之前得出的网衣与波浪相互作用结论进一步研究了网箱对波浪传播的影响,同时研究了网箱形状、网衣密实度等参数改变对波浪场的影响,最后研究了网箱的波浪水动力特性。
[Abstract]:In recent years, with the increasing demand for marine fishery products, wild marine organisms are overfished. At the same time, the high-speed economic development brings about the pollution of offshore industry, which makes the ecological environment of offshore waters deteriorate gradually. With the increase of demand and the deterioration of living environment, fishery resources are nearly exhausted, and the market demand exceeds supply. In order to solve the above problems, deep-sea cage culture has developed rapidly in recent years. Compared with offshore aquaculture, deep-sea aquaculture means stronger wind, wave and current conditions, and cage is easy to be destroyed in this bad environment. At the same time, the culture environment such as current and wave in the net box is closely related to the growth of fish. As an important part of aquaculture cage, fishing net is a kind of complex flexible structure. In view of the above situation, we first carried out the physical model test and corresponding numerical simulation, studied the influence of the net coat on the wave propagation, and found out the interaction mechanism and law between the net coat and the wave. On this basis, the hydrodynamic characteristics of waves and cages and the effects of cages on wave propagation are further studied. In this paper, the CFD software FLUENT is applied to numerical simulation, and a three-dimensional numerical wave flume model is established to simulate the interaction between the net coat and the wave by using the porous medium model. Based on the numerical model, the variation law of wave height attenuation after the wave passing through the net is studied, and the results are compared with the results of the physical model test. By comparing the results of numerical simulation and physical model test, the feasibility of simulating the effect of the net coat on wave propagation is proved by the three-dimensional numerical model. The thesis consists of five chapters: the first chapter is an introduction, which briefly introduces the research background, purpose and research progress at home and abroad. The second chapter introduces the mathematical methods of the numerical model, including the governing equation, the transformation between the porous media model and the mesh, the establishment of the three-dimensional numerical wave tank and its mesh division, and the mathematical principles of wave generation and wave elimination in the numerical wave tank. In chapter 3, the effectiveness of wave suppression in numerical wave flume is first verified, and then the wave field around the net is simulated by numerical model, and the physical model experiment is carried out to verify the wave field around the net, and the mechanism of the action between the net and the wave is preliminarily understood. The influence of net clothing on wave propagation is obtained. In chapter 4, the influence of different depth of mesh on wave propagation and the influence of changing the number of mesh on the wave field are studied. In chapter 5, the influence of cage on wave propagation is further studied according to the conclusion of the interaction between netting and wave, and the influence of the shape of cage and the density of netting on the wave field is also studied. Finally, the wave hydrodynamic characteristics of cages are studied.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：S967.3;P731.2

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