臺灣博碩士論文加值系統

台灣西南方-北南海陸波上，有許多因海洋內波所造成的特殊地形-沙丘。沙丘分布在160公尺至600公尺水深，發現其振幅最大可達16公尺，導致此海域的水下音傳會受到沙丘地形影響，而產生三維擾動效應。本文將使用拋物線方程式(parabolic equation)為基礎的數值模式進行模擬，數值模式可分為二維拋物線方程式(RAM)以及可計算三維拋物線方程式(FOR3D)的模式進行模擬計算，而模擬結果是否正確取決於許多因素，其中初始場佔有很大的影響力。根據過去的模擬結果發現RAM所使用的初使場(self starter)會出現過分初始化的現象而影響模擬結果，且為確保模擬結果正確需找出符合實驗聲源的初始條件，故本文將針對初始場的問題進行探討，並使用合適的初始場模擬2014年於此海域所獲得相關實驗資訊進行聲學模擬比對，分別以二維及三維傳播模式探討，分析南海沙丘對水下音傳所造成的三維擾動效應。

There are many underwater sand dunes caused by the internal wave located in the depth of 160 meters to 600 meters in northern South China Sea. The largest amplitude of these sand dunes is about 16m. Underwater acoustic transmission is affected by this topographic feature, and also has three dimensional effects. In this research the 2-D and 3-D underwater acoustic propagation models (RAM and FOR3D respectively), are used to simulate acoustic propagation in the region. There is starter issue to be resolved for the high-impedance, low-loss ocean bottom of the region. RAM with self-starter is overly initialized, thus the initial field is produced to match with the source beam-pattern. A tunable Gaussian starter is then used to avoid over initialization, which is a proper starter for the moored source. The acoustic field received at VLA emitted from the moored source is simulated with the proper starter. Results show temporal variations with respect to that of water column, and three dimensional effects over sand dunes.

目錄
誌謝 i
中文摘要 ii
ABSTRACT iii
目錄 iv
符號目錄 vi
圖目錄 vii
表目錄 xii
第一章 緒論 1
1.1 前言 1
1.2研究動機及目的 2
1.3 文獻回顧 2
1.4論文架構 5
第二章 2014年北南海沙丘實驗 6
2.1 實驗介紹 6
2.1.1 實驗目的 6
2.1.2 實驗規劃 6
2.2實驗資料 14
第三章 研究方法 20
3.1 二維拋物線方程式 20
3.2 Self-Start 22
3.3 三維效應分類 23
3.4 Lee-Saad-Schultz (LSS)數學模式 24
第四章 模式參數設定 27
4.1 初始場修正 27
4.1.1 FOR3D with Standard Gaussian Starter 27
4.1.2 RAM with Standard Gaussian Starter 28
4.1.3 符合聲源之初始場 40
4.2 探討FOR3D角度限制 45
4.3 合適距離變化量 49
第五章 模擬結果 53
5.1 地形比較 53
5.2聲速隨時間變化於無沙丘地形 57
5.3聲速隨時間變化於沙丘地形 58
5.4 三維音傳模擬 61
第六章 結論與未來工作 66
6.1 結論 66
6.2 未來工作 67
參考文獻 72
附錄A 聲速隨時間變化於沙丘地形(每15分鐘) 74
附錄B TUDAS-32各麥克風於2014年6月9日隨時間變化的音傳損耗 86
附錄C RAM之程式碼 102
附錄D ram.in格式範例 106

參考文獻
[1]S. Boggs, "Sand-wave fields in Taiwan Strait," Geology, vol. 2, pp. 251-253, 1974.
[2]劉孟竺, "三維海洋音傳與海床沙丘效應之研究," 2014.
[3]葉翰融, "北南海陸坡沙丘地形之三維水下音傳之研究," 國立臺灣大學工程科學及海洋工程學研究所學位論文, pp. 1-66, 2015.
[4]A. Tolstoy, "3-D propagation issues and models," Journal of Computational Acoustics, vol. 4, pp. 243-271, 1996.
[5]F. D. Tappert, "The parabolic approximation method," in Wave propagation and underwater acoustics, ed: Springer, 1977, pp. 224-287.
[6]R. N. Baer, "Propagation through a three‐dimensional eddy including effects on an array," The Journal of the Acoustical Society of America, vol. 69, p. 70, 1981.
[7]J. S. Perkins and R. N. Baer, "An approximation to the three‐dimensional parabolic‐equation method for acoustic propagation," The Journal of the Acoustical Society of America, vol. 72, p. 515, 1982.
[8]D. Lee, Y. Saad, and M. H. Schultz, "An efficient method for solving the three-dimensional wide angle wave equation," DTIC Document1986.
[9]S. V. Richard, "Matrix iterative analysis," ed: Prentice-Hall, Englewood Cliffs, NJ, 1962.
[10]D. Lee and M. H. Schultz, Numerical ocean acoustic propagation in three dimensions: World scientific, 1995.
[11]C. CHEN, Y.-T. LIN, and D. Lee, "A three-dimensional azimuthal wide-angle model for the parabolic wave equation," Journal of Computational Acoustics, vol. 7, pp. 269-286, 1999.
[12]L.-W. Hsieh, C.-F. Chen, M.-C. Yuan, and Y.-T. Lin, "Azimuthal limitation in 3D PE approximation for underwater acoustic propagation," Journal of Computational Acoustics, vol. 15, pp. 221-233, 2007.
[13]E. Shang and Y. Wang, "Acoustic travel time computation based on PE solution," Journal of Computational Acoustics, vol. 1, pp. 91-100, 1993.
[14]陳屛先, "海洋聲學傳播模組分析," National Taiwan University Department of Naval Architecture and Ocean Engineering., 1998.
[15]林志銘, "三維海洋聲音模組分析硏究," National Taiwan University Department of Naval Architecture and Ocean Engineering., 1999.
[16]林正偉, "三維數值模擬之格點重訂技術," 國立臺灣大學工程科學及海洋工程學研究所學位論文, pp. 1-43, 2011.
[17]劉育維, "三維水下音傳局部卡氏座標模式," 國立臺灣大學工程科學及海洋工程學研究所學位論文, pp. 1-54, 2011.
[18]A. Newhall, L. Costello, T. Duda, J. Dunn, and G. Gawarkiewicz, "Preliminary acoustic and oceanographic observations from the ASIAEX 2001 South China Sea experiment," DTIC Document2001.
[19]T. F. Duda, J. F. Lynch, A. E. Newhall, L. Wu, and C.-S. Chiu, "Fluctuation of 400-Hz sound intensity in the 2001 ASIAEX South China Sea experiment," Oceanic Engineering, IEEE Journal of, vol. 29, pp. 1264-1279, 2004.
[20]C.-S. Chiu, S. R. Ramp, C. W. Miller, J. F. Lynch, T. F. Duda, and T. Y. Tang, "Acoustic intensity fluctuations induced by South China Sea internal tides and solitons," Oceanic Engineering, IEEE Journal of, vol. 29, pp. 1249-1263, 2004.
[21]Y.-S. Chiu, Y.-Y. Chang, L.-W. Hsieh, M.-C. Yuan, and C.-F. Chen, "Three-Dimensional Acoustics Effects In The Asiaex Scs Experiment," Journal of Computational Acoustics, vol. 17, pp. 11-27, 2009.
[22]K. Wyckoff, M. Stone, C. W. Miller, and F. Bahr, "The Windy Island Soliton Experiment (WISE): shallow water and basin experiment configuration and preliminary observations," 2009.
[23]D. Reeder, "Acoustic Propagation Studies in the Nonlinear Internal Wave Initiative (NLIWI) in the South China Sea (SCS)," DTIC Document2007.
[24]D. B. Reeder, L. Y. CHIU, and C.-F. Chen, "Experimental evidence of horizontal refraction by nonlinear internal waves of elevation in shallow water in the South China Sea: 3D versus Nx2D acoustic propagation modeling," Journal of Computational Acoustics, vol. 18, pp. 267-278, 2010.
[25]D. B. Reeder, B. B. Ma, and Y. J. Yang, "Very large subaqueous sand dunes on the upper continental slope in the South China Sea generated by episodic, shoaling deep-water internal solitary waves," Marine Geology, vol. 279, pp. 12-18, 2011.
[26]C. W. C. Miller, Ching-Sang;Reeder, D.Benjamin; Yang, Ying-Jang; Chiu,Linus;Chen,Chi-Fang, "Preliminary observations from the 2014 Sand Dunes experiment," 2014-10.
[27]M. D. Collins, "Users Guide for RAM Versions 1.0 and 1.0 p," Naval Research Lab, Washington, DC, vol. 20375, 1995.
[28]F. B. Jensen, W. A. Kuperman, M. B. Porter, and H. Schmidt, Computational ocean acoustics: Springer Science & Business Media, 2011.
[29]M. D. Collins, "A self‐starter for the parabolic equation method," The Journal of the Acoustical Society of America, vol. 92, pp. 2069-2074, 1992.
[30]D. Lee and S. McDaniel, Ocean acoustic propagation by finite difference methods vol. 15: Elsevier, 2014.