陳琪芳臺灣大學：工程科學及海洋工程學研究所陳彥勳Chen, Yen-HsunYen-HsunChen2007-11-262018-06-282007-11-262018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/51012本文目的為比較ASIAEX南海實驗音傳損耗(Transmission Loss)的資料與數值模擬結果，並探討水文及底質特性對淺海聲音傳播的影響。文中主要探討在ASIAEX南海實驗中，J-15-3第二條拖曳路徑中(5月5日23：31到5月6日00：23之間) CW訊號在140Hz時的音傳損耗，並將其理論計算與實際資料相比，發現數值模擬可因水文(內波)及底質參數之輸入調整，而與資料結果相仿，因此探討水文及底質特性問題。底質算例結果顯示底層聲速越高其音傳損耗越小，由聲源頻率50∼300Hz的結果發現，聲源頻率越低底層有效深度越深，而聲源頻率增加其有效深度則減少。水文算例結果顯示由內波所產生的音傳擾動會更加紊亂，因而在實際水文環境中，找出內波切確位置及速度就極為重要。The comparison between the data of the transmission loss in the ASIAEX SCS experiment and the result of the numerical simulations is presented in this paper. In addition, we try to discuss the effect of water column and sediment property on the acoustic propagation in the ocean. In this paper, we mainly discuss the transmission loss of CW tones transmitted in 140 Hz during a segment of J-15-3 RUN2 which started at 05/05 23:31 and ended in 05/06 00:23. Furthermore, according to the comparison between theoretical calculations and practical data, we found the result of the numerical simulations would be similar to the practical data if the parameter of water column (internal wave) and sediments are corrected. Therefore, it is necessary to consider water column as well as sediment property further. The result of the calculation of the sediment shows the transmission loss would get lower as the sound speed gets higher and in 50-300Hz range, the effect depth of the sediment is an inverse proportion to the source frequency. The results of water column case show that due to internal waves, the fluctuation in sound propagation becomes severer. Therefore it is very important to find out the exact locations and speed of internal waves in the real ocean environment.致謝及感言 ……………………............I 中文摘要…………………………………………………II Abstract…………………………………………………III 目錄………………………………………………………IV 圖表目錄…………………………………………………VI 第一章 緒論……………………………………………1 1.1 背景介紹…………………………………………1 1.2 研究動機與目的…………………………………1 1.3 文獻蒐集…………………………………………5 1.4 研究方法…………………………………………7 1.4.1 PE拋物線方程式…………………………7 1.4.2 Normal Modes……………………………10 1.4.3 MOS3DPEF……………………………………….14 1.5 論文架構………………………………………….16 第二章 ASIAEX J-15-3 RUN2實驗分析及數值模擬……17 2.1 ASIAEX J-15-3 實驗簡介………………………18 2.1.1 實驗配置及步驟………………………………19 2.1.2 實驗區域海洋環境簡介………………………21 2.2 實驗訊號處理……………………………………28 2.3 數值模擬…………………………………………31 2.3.1 海洋音響環境建立……………………………31 2.4 結果與討論……………………………………………35 2.4.1實驗數據及數值模擬結果比較………………..35 2.4.2相關問題延伸…………………………………..42 第三章 淺海環境中底質特性對音傳之影響……………44 3.1 淺海底質對聲學性質之影響…………………………45 3.2 Hamilton之地音模型建立………………………….47 3.3 底質特性對音傳損耗的影響…………………………56 3.4 底質特性對音傳模組之影響…………………………65 3.4.1 不同底質的有效深度…………………………66 3.4.2 底層計算深度結果……………………………71 第四章 淺海環境水文對音傳影響…………………………79 4.1 內波對音傳損耗之影響………………………………79 4.1.1不同位置之內波對音傳之影響………………82 4.2 內波對模組之音傳影響…..……………………88 第五章 結論及未來研究方向…………………………100 參考文獻…………………………………………………10413920665 bytesapplication/pdfen-US淺海環境音傳特性Shallow WatersSound Propagationthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51012/1/ntu-93-R91525019-1.pdf