SWAN模式渤海湾海浪数值模拟研究

KEY WORDS：Bohai bay, WRF model, wave, SWAN , numerical simulation
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目 录
第一章 绪论.......................................................................................................... 1 1.1 研究意义 ................................................................................................. 1 1.2 海浪预报研究进展 ......................................................................... 1 1.2.1 波浪模式概述 .............................................................................. 1 1.2.2 国外海浪数值模式研究现状 ...................................................... 2 1.2.3 国内海浪模式应用现状 ............................................................. 4 1.3 本论文的主要研究内容 ................................................................. 5 第二章 SWAN 模式简介 ..................................................................................... 6 2.1 SWAN 模式控制方程 ............................................................................. 7 2.2 物理过程 ................................................................................................. 8 2.2.1 风能输入项 S in ............................................................................. 8 2.2.2 白浪耗散项 S w c .......................................................................... 10 2.2.3 底摩擦耗散项 S bot .................................................................... 12 2.2.4 水深诱导破碎耗散项 Sbr ......................................................... 13 2.2.5 非线性相互作用项 S nl ............................................................... 14 2.2.6 波生流计算................................................................................. 16 2.3 数值方法 .............................................................................................. 16 2.3.1 方程离散化 ................................................................................ 17 2.3.2 源、汇项求解 ............................................................................ 19 2.4 初始场与边界条件 ............................................................................... 20 2.5 程序及并行模块 ................................................................................... 20 第三章 WRF 数值预报模式简介 ...................................................................... 24 3.1 WRF 模式概述 ...................................................................................... 24 3.2 模块介绍................................................................................................ 24 3.2.1 WRF-ARW 控制方程及物理参数 ............................................ 25 3.2.2 数据同化模式 WRF-DA ............................................................ 27 第四章 SWAN 海浪模式参数选择 ................................................................... 29 4.1 计算海区 ............................................................................................... 29 4.2 地形、风场资料 ................................................................................... 30 4.2.1 地形资料来源与处理................................................................. 30 4.2.2 风场资料 .................................................................................... 31 4.2.3 风场过程 .................................................................................... 33
SWAN 模式渤海湾海浪数值模拟研究 Research on numberical simulation wave in bohai bay by SWAN model
（申请硕士学位）
学科专业：水利工程 研 究 生：罗浩 指导教师：李大鸣 教授
天津大学建筑工程学院 二零一二年十一月
独创性声明
本人声明所呈交的学位论文是本人在导师指导下进行的研究工作和取得的 研究成果，除了文中特别加以标注和致谢之处外，论文中不包含其他人已经发表 或撰写过的研究成果， 也不包含为获得 天津大学 或其他教育机构的学位或证 书而使用过的材料。 与我一同工作的同志对本研究所做的任何贡献均已在论文中 作了明确的说明并表示了谢意。
关键词：渤海湾； WRF 模式；波浪；SWAN；数值模拟
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ABSTRACT
The ocean wave is a major marine disaster, it is vital important and significance that researching wave development, grow and real-time numerical prediction to the fishery fishing, sea transportation and construction and sea military activities, etc. This article utilizes third generation shallow ocean waves pattern SWAN 40.84(Simulating Waves Nearshore) ,as well as high-precision mesoscale atmospheric model WRF (Weather Research and forecast) numerical pattern predicting wind farms,builds and verifys SWAN model which is suitable to simulate bohai bay wave. We separately study linearity growth and the exponential growth of inputting wind by choosing two weather process from WRF model basing on wind stress calculation method.The research show that we should consider the linear growth item in the SWAN pattern.For three exponential expressions of wind input and corresponds to white waves breaking expression in SWAN pattern,we design portfolio,Komen programme,Janssen programme and Westhuysen programmes,to research the SWAN model applicability in simulating Bohai bay wave under difference combination programmes.we compare simulation results of three portfolio with measured data，the result shows that average period of three programs are relatively small，howerer， significant wave height of simulation is close to measured datd. Westhuysen saturated threshold program scenario simulations work best in statistical analysis of the simulation result. We modifiy wind stress drag coefficient and water depth–induce break coefficient in westhuysen form to improve wave simulation accuracy under WRF wind pattern. Finally,we design the swan-swan three levels self-nesting methods to simulate Bohai Bay wave, and validate simulation results, wave height and period ,agree better with the measured data than before,This confirm the established mathematical model SWAN is suitable to wave forecsting in Bohai bay .