English  |  正體中文  |  简体中文  |  Items with full text/Total items : 74010/74010 (100%)
Visitors : 24684854      Online Users : 275
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/65004

    Title: 裙礁流場之數值分析與消能特性之探討;Numerical Simulation on the Flow Field and Energy Dissipation by the Fringing Reef
    Authors: 黃培軒;Huang,Pei-Hsuan
    Contributors: 水文與海洋科學研究所
    Keywords: 裙礁;大渦模擬;能量消散;流體體積法;珊瑚礁脊;三維模擬;fringing reef;LES;energy dissipation rate;VOF;ridge;3-D simulation
    Date: 2014-08-21
    Issue Date: 2014-10-15 14:37:55 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 裙礁為一種典型之珊瑚礁型式,主要由珊瑚礁灘(reef flat)和珊瑚礁坡(reef slope)所組合而成。其中珊瑚礁灘通常存在於較淺之海岸邊並且毗鄰陸地,其坡度較礁坡為平緩,可對波浪有消能效果。珊瑚礁坡離海岸較遠,坡度亦較為陡峭,因波浪由深水段傳遞到較淺之珊瑚礁灘上時經常直接造成波浪反射和伴隨碎波之產生。為了深入了解能量消散機制,本研究透過理想化珊瑚礁之實驗與數值模擬來探討其流場特性。在數值模擬方面,採用Large-Eddy Simulation (LES) 紊流模型並搭配Volume of Fluid (VOF) 法,為精準描述實驗室造波機所產生之入射波,本研究使用moving-solid algorithm (MSA)模擬造波機推板之運動,並針對無ridge之案例進行三維數值分析。
    ;The fringing reef is a common type of coral reef which is mainly by the reef flat and reef slope. The reef flat is usually found in the shallow water area with a mild slope. Because the reef flat is adjacent to land, it plays an important role on dissipating the wave energy. Reef slope, on the other hand, is often quite steep which reflects the wave energy directly and introducing wave breaking. In order to have profound understanding on the energy dissipating mechanism, we idealize the reef setup and explore the flow field numerically. We performed the numerical simulation by solving the Large-Eddy Simulation (LES) model with volume of fluid (VOF) interface tracking algorithm. To accurately describe the incident wave generated by a piston-type wavemaker, we utilized the moving-solid algorithm (MSA). Furthermore, the case without a ridge was chosen for demonstrating the 3-D effect of the flow field. By comparing the numerical result and the experimental data, the differences of flow velocity at middle depth and free surface-elevation were less than 5%. Energy dissipation rate for 1:10 slope is 12% greater than on the 1:1 slope. Dissipation rate of the still water depth 0.4m is 1.2% greater than the one of the still water depth 0.5m. Also, Long wave period has lager energy dissipation rate. In the case of 3-D simulation, the results show that the 3-D effect was observed after wave breaking. The differences between the 2-D and 3-D are less than 5% in terms of both the wave height and velocities. Energy dissipation rate between 2-D and 3-D simulations is less than 1%. Detailed analysis are shows in the context.
    Appears in Collections:[水文與海洋科學研究所] 博碩士論文

    Files in This Item:

    File Description SizeFormat

    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 隱私權政策聲明