English  |  正體中文  |  简体中文  |  Items with full text/Total items : 26988/38789
Visitors : 2357181      Online Users : 31
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/39942

Title: 以布斯尼斯克模式探討花蓮港港池共振現象
Authors: 鄭欽鐘
蔡政翰
Contributors: 國立臺灣海洋大學:海洋環境資訊學系
Date: 2004-11
Issue Date: 2017-01-10T06:41:06Z
Abstract: 花蓮港港池共振已是個長久的問題。導致許多船舶必須在颱風抵達之前離港。許多數值模擬已經試著去了解此共振問題,然而大部份的研究都是使用規則波模式,比如緩坡方程式模式。本研究以布斯尼斯克波浪模式(MIKE21-BW)來模擬入射花蓮港的波浪。本研究以週期25秒∼1000秒能量密度相等的白噪頻譜模擬入射波。以其模擬結果分析各碼頭的波浪頻譜及波高增幅係數。其次以接近週期100秒的規則波與不規則波為入射波浪。本研究也以安珀颱風在花蓮港外海的實測波浪資料模擬。
數值計算結果顯示,當規則波週期80秒∼100秒、135秒∼145秒及185秒時為花蓮港的振盪週期。規則波模擬結果也顯示,雖然花蓮港水面振盪是以縱深方向為主,但在22號碼頭及東防波堤間當週期為80秒、125秒、130秒及135秒時有橫向的振盪發生。另由白噪頻譜模擬所得的振盪週期相當接近於以實測颱風資料模擬的結果。由此可知使用白噪頻譜來研究港池共振是一個有效率的方式。因此亦可使用白噪頻譜及BW模式來進一步探討減輕花蓮港港池振盪現象的方法。

Abstract: Resonance in the Hwa-Lien Harbor has long been a problem for the harbor authority. Many ships have had to leave the harbor before arrivals of typhoon. Many numerical simulations had been carried out trying to understand this resonance phenomenon. However, most of the numerical studies used wave models based on regular waves, such as mile-slope equation model. This study used a Boussinesq wave model (MIKE21-BW) to simulate the waves in the harbor. The present study first generate waves with period ranging from 25s to 1000s periods with uniform spectral density, or waves with white noise spectrum, as incident waves. The resulting spectrum and wave amplification factor were calculated for various wharfs. Similarly regular as well as irregular waves with wave periods near 100s were used as incident waves. The simulations were also carried out using waves measured offshore of the harbor during the Typhoon Amber.
It was found from regular wave simulation that resonant periods in the harbor were 80s~100s, 135s~145s and 185s. Regular wave simulation also showed that, although the resonant phenomenon in the harbor occurred lengthwise, there exist another mode, which occurred transversely between wharf 22 and the eastern breakwater with period of 80s, 125s, 130s and 135s. Resonant period from the white noise spectrum simulation were shown to close to that using measured typhoon waves. This indicates that using white noise spectrum is an efficient method for studying harbor resonance. Apparently, one can also use white noise spectrum and the BW model to study ways for alleviating resonance phenomenon in the Hwa-Lien Harbor.
URI: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/39942
Appears in Collections:[海洋環境資訊系] 演講及研討會

Files in This Item:

File Description SizeFormat
index.html0KbHTML37View/Open


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

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback