基于N-S方程不同简化形式海洋灾害数学模型的应用研究

发布时间：2018-01-18 09:42

本文关键词：基于N-S方程不同简化形式海洋灾害数学模型的应用研究　出处：《天津大学》2016年博士论文　论文类型：学位论文

【摘要】：我国海岸线绵长、海域面积广大,是一个海洋大国。各种海洋灾害的发生威胁了沿岸居民和出海人员的生命安全,也造成了巨大的经济损失。海洋灾害的种类很多,其中海啸、风暴潮、溢油是几种典型的海洋动力和环境灾害。海洋灾害数学模型的研究可为各种海洋灾害科学预警提供依据。海洋灾害数学模型的基础是建立较高精度的水动力场,依据不同灾害产生的原因附加不同的作用场。本文系统推导了三维纳维-斯托克斯方程的垂向积分形式。提出海洋灾害数学模型是不同控制方程、考虑因素、离散方法的组合模型,组合模型的基础是纳维-斯托克斯方程。以此思想为出发点,本文建立了四种形式的海洋灾害数学模型。(1)系统地总结了几种海洋灾害数学模型的离散形式和控制方程。以风暴潮灾害、海上溢油灾害、垂向二维油膜水体运动模型为实例,分别介绍了ADI差分格式、有限元法的离散过程、SPH方法的建模过程。以海啸数学模型为实例介绍了以Boussinesq方程为控制方程的波浪模型。以风暴潮和海上溢油模型为实例介绍了浅水环流方程为控制方程的水动力模型。(2)建立了 2011年日本海啸的局地海啸数学模型,模型包括海啸源初始位移场模型和海啸波传播模型。在海啸源模型中考虑不同海底地形的初始场,根据水面与海底地形变化体积相同的等水体量法,确定了圆形和狭长型变形体积系数。海啸波传播模型以Boussinesq方程为控制方程,以ADI方法为离散方式,提出了增加以辐射应力为作用形式的能量变化项,模拟了海啸波能量传播过程,并对波动水边界提出了改进方法。模型计算波高及其到达时间与实测值吻合较好。(3)建立了黄渤海风暴潮数学模型。模型采用浅水环流方程作为潮流计算控制方程,同时考虑风场和SWAN模式计算的波浪场,对波浪辐射应力作用的风暴潮计算增水影响进行了研究。结果表明辐射应力对流速影响较明显,对水位影响不大。(4)建立了基于SPH方法的垂向二维油膜水体运动数值模型。对水上、水下油膜运动以及波浪条件下油膜运动进行了研究。探讨了不同密度、不同粘性水油运动模式对模型结果的影响。提出了密度重分布法和过渡粒子法,对油水两相流模型进行了改进。模型计算油膜扩展尺度和时间与费伊模型计算结果相关系数为0.998。(5 )建立了栾家口港海上溢油数学模型。模型中综合考虑了潮流、风波、油膜等多种运动因素。提出了包括油膜边界运动模式和吸附边界处理模式的多岛屿海域油膜扩移的模拟方法,在油膜边缘内部考虑油品挥发和铺展的厚度,在近岸和岛屿附近考虑油膜吸附和乳化作用。应用模型建立了不同动力条件、溢油点、油品种类、溢油方式的30个溢油情景。对不同情景油膜的运动轨迹和油膜覆盖面积进行了分析。
[Abstract]:China has a long coastline and vast sea area. It is a large marine country. The occurrence of various marine disasters has threatened the lives of coastal residents and sea people. It also caused huge economic losses. There are many kinds of marine disasters, including tsunamis and storm surges. Oil spill is a typical marine dynamic and environmental disaster. The study of marine disaster mathematical model can provide the basis for scientific early warning of various marine disasters. The foundation of marine disaster mathematical model is to establish a high precision hydrodynamic field. In this paper, the vertical integral form of three-dimensional Navier-Stokes equation is derived according to the cause of different disasters, and the mathematical model of marine disaster is put forward, which is different control equation, and the factors are taken into account. The combined model of discrete method is based on the Navier-Stokes equation. In this paper, four kinds of marine disaster mathematical models are established. (1) the discrete forms and control equations of several marine disaster mathematical models are summarized systematically. The vertical two-dimensional oil film water motion model is used as an example to introduce the discrete process of ADI difference scheme and finite element method. The modeling process of SPH method. Taking the tsunami mathematical model as an example, the wave model with Boussinesq equation as governing equation is introduced. The shallow water circulation square is introduced by taking storm surge and offshore oil spill model as examples. A hydrodynamic model with a governing equation. 2) the local tsunami mathematical model of 2011 tsunami in Japan is established. The model includes the initial displacement field model of the tsunami source and the tsunami wave propagation model. The initial field of different submarine topography is considered in the tsunami source model. The wave propagation model takes Boussinesq equation as the governing equation and ADI method as the discrete mode. An energy change term in the form of radiation stress is proposed to simulate the energy propagation process of the tsunami wave. An improved method is proposed for the boundary of fluctuating water. The calculated wave height and its arrival time are in good agreement with the measured values. A mathematical model of storm surge in the Yellow Sea and Bohai Sea is established. The shallow water circulation equation is used as the governing equation of tidal current calculation. At the same time, considering the wind field and the wave field calculated by SWAN model, the effect of storm surge calculation on wave radiation stress is studied. The results show that the effect of radiation stress on velocity is obvious. The numerical model of vertical two-dimensional oil film water movement based on SPH method is established. The oil film motion under water and wave conditions is studied. The effects of different density and different viscous water and oil motion modes on the model results are discussed. The density redistribution method and the transition particle method are proposed. The oil-water two-phase flow model is improved. The correlation coefficient between the model and the Fay model is 0.998.5. A mathematical model of oil spill in Luanjiakou port is established. The tidal current is taken into account in the model. Wind wave, oil film and other moving factors. A simulation method of oil film expansion in multi-island sea area including oil film boundary motion model and adsorption boundary treatment model is proposed. The thickness of oil volatilization and spread is considered in the edge of oil film, and the adsorption and emulsification of oil film are considered near shore and island. Different dynamic conditions, oil spill point and oil product type are established by using the model. In this paper, 30 oil spill scenarios of different oil spill modes were used to analyze the motion track and the covering area of oil film in different scenarios.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P73;X43

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