沙质海岸剖面演化数值模型研究

发布时间：2018-04-02 03:12

本文选题：沙质海岸　切入点：海岸水动力　出处：《大连理工大学》2014年硕士论文

【摘要】：沙质海岸是一种常见的海岸类型,主要由较粗的颗粒组成,如砂、砾、卵石等。具有岸滩较窄、岸线平顺、坡度较陡的形态特点,是发展渔港、旅游、沿海养殖的理想场所,具有重要的经济价值。近些年来,自然环境的改变加之人为因素的干扰,我国的沙质海岸的侵蚀逐步加剧,在影响生态环境的同时,也给社会经济的发展造成不可估量的损失。因此,对灾害性海岸泥沙运动进行研究,为防止不利的海岸变形和充分发挥海岸变形在社会经济发展中的有利作用具有重大的意义。本文建立了基于有限差分方法(FDM)与有限体积方法(FVM)混合求解的新型Boussinesq波浪数值模型,并将其作为驱动力与边界层模型、输沙模型和地形更新模型耦合形成基于动力过程的岸滩剖面演变数值模型,对波浪作用下沙质岸滩的变形进行研究,文章主要内容包括： 1.新型Boussinesq类波浪数值模型的建立基于Boussinesq水波方程的波浪模型能够描述近岸区域波浪传播、变形、爬坡、非线性流体运动等动力因素,成为研究海岸泥沙的有力工具。然而,现有的Boussinesq类波浪数值模型多采用有限差分方法进行求解,这种方法有简单明了,编程容易等优点。但基于有限差分求解的Boussinesq数学模型存在一些不容忽视的弊端：稳定性差、采用经验方式处理波浪破碎和干湿动边界、诸多参数的引入导致应用不便。本文建立了基于有限差分和有限体积方法混合求解Boussinesq方程的波浪数值模型,模型具有稳定性强、易于处理波浪破碎和捕捉海岸动边界等优点。 2.基于动力过程的岸滩剖面演化数值模型的建立通过求解边界层模块获得底部剪切应力,进而求得输沙率,采用高精度格式求解地形更新方程,采用守恒格式进行地形光滑。将本文建立的新型Boussinesq类波浪数值模型作为驱动力耦合上述诸模块形成基于动力过程的岸滩剖面演变数值模型,对波浪作用下沙质岸滩剖面的变形进行了数值模拟研究。
[Abstract]:Sandy coast is a common coastal type, mainly composed of coarse particles, such as sand, gravel, pebbles, etc.It has the characteristics of narrow shoreline, smooth shoreline and steep slope. It is an ideal place for developing fishing port, tourism and coastal culture, and has important economic value.In recent years, with the change of natural environment and the disturbance of human factors, the erosion of sandy coast in our country is gradually intensified, which not only affects the ecological environment, but also causes incalculable losses to the development of social economy.Therefore, it is of great significance to study the disastrous coastal sediment movement in order to prevent the adverse coastal deformation and give full play to the favorable role of coastal deformation in the social and economic development.In this paper, a new Boussinesq wave numerical model based on the finite difference method (FDM) and the finite volume method (FVM) is established and used as the driving force and the boundary layer model.The sediment transport model and the topographic renewal model are coupled to form a numerical model of shoreline profile evolution based on dynamic process. The deformation of sandy shoreline under wave action is studied. The main contents of this paper are as follows:1.Establishment of a new Boussinesq wave numerical modelThe wave model based on Boussinesq's water wave equation can describe the dynamic factors such as wave propagation, deformation, slope climbing and nonlinear fluid movement in the coastal area. It is a powerful tool for studying coastal sediment.However, most of the existing Boussinesq wave numerical models are solved by finite difference method, which has the advantages of simplicity and simplicity, easy programming and so on.However, the Boussinesq mathematical model based on finite difference solution has some drawbacks that can not be ignored: poor stability, the treatment of wave breakage and dry-wet boundary by empirical method, and the inconvenience of application due to the introduction of many parameters.In this paper, a wave numerical model based on finite difference and finite volume method for solving Boussinesq equation is established. The model has the advantages of strong stability, easy to deal with wave breakage and to capture the moving boundary of the coast.2.Establishment of a numerical model of shoreline profile evolution based on dynamic processThe bottom shear stress is obtained by solving the boundary layer module, and the sediment transport rate is obtained. The topographic updating equation is solved with high precision scheme, and the terrain is smooth with conservation scheme.The new Boussinesq wave numerical model is used as a driving force to couple the above modules to form a dynamic process based numerical model of shoal profile evolution. The deformation of sandy shoreline profile under wave action is numerically simulated.
【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】：P737.1

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