隱匿性對於潛艇而言相當重要，水下開口腔體結構所產生的水動力噪音之所以可以成為潛艇減震降噪所關注的重要議題，是因為水動力噪音是潛艇三大主要噪聲源之一，而潛艇表面的水櫃開口結構是最有可能產生低頻率峰值輻射噪音之來源，因此有必要針對此結構了解其噪音與流體流動特性。
本研究先以雷諾數相似的腔體實驗資料作為驗證對象，首先利用電腦設計軟體SolidWords進行模型繪製，再利用計算流體力學軟體 Fluent軟體，基於大型渦流模擬與 Lighthill理論對驗證腔體進行數值模擬計算，將其結果與公開發表之實驗資料進行對比，確認數值模擬具有一定程度之可行性與準確性後，再針對本研究所設計的水下腔體結構進行模擬計算，通過改變入流速度、開口角度、開口長寬比和雙孔不同間距等四項操縱變因來 進行因次分析並了解各構型之噪音與流場差異。
最後經由數值方法結果發現水下腔體內流場相對穩動，主要流動差異集中在開口處，而入流速度與噪音值和振盪頻率皆成正比關係，開口長度與振盪頻率成反比關係，以及發現改變開口角度可以有效改變其輻射噪音，在本研究所設計的構型前提下，以60度開口角度所產生的輻射噪音值最小，另外在開口面積相等的情況下單口輻射噪音明顯大於雙口設計 應採用雙口縱列來取代單一開口 。

Stealthiness is very important for submarines. Hydrodynamic noise is one of the three main sources of noise in submarines. The open cavity on the surface of submarines is the most likely source of low frequency radiated noise. Thus, it is necessary to examine this structure in understanding the characteristic of its noise and fluid flow.
This research begins with the cavity experiment data, which is similar to Reynolds number, as the test subject. Initially, the computer design software SolidWords is utilized for modeling, followed by the computational fluid dynamics software FLUENT. Numeric simulation for verifying the cavity is made based on both the theory of large eddy simulation, and the Lighthill theory. The results are then compared with the published experimental data, confirming that the numerical simulation has a degree of feasibility and accuracy. The underwater cavity structure, designed by this research institution, then undergoes simulation. The noise and flow field difference of each configuration were analyzed by changing the input velocity, opening angle, opening aspect ratio and double hole spacing.
Finally, through the study, it is discovered that the underwater cavity flow field in the body is relatively stable, the main flow divergence occurs at the opening. The inflow rate, noise value and is proportional to the oscillation frequency; the opening length is inversely proportional to the oscillation frequency. It is also discovered that changing the opening angle can effectively alter the radiation noise, under the premise of the design configuration in our study, a 60-degree opening angle generates the least amount of radiation noise. Additionally, under the condition that the opening area is the same, the stand-up radiation noise is significantly greater than that of the double cavity design. Thus the double cavity columns should be adopted to replace a single opening.

Curle, N. (1955). The influence of solid boundaries upon aerodynamic sound. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 231(1187), 505-514.
De Roeck, W.; Desmet, W.;Baelmans, M., & Sas, P. (2004). On the prediction of near-field cavity flow noise using different CAA techniques. Aeroacoustics and Flow Noise Proceedings of ISMA, 369-386.
Deardorff, J. W. (1970). A numerical study of three-dimensional turbulent channel flow at large Reynolds numbers. Journal of Fluid Mechanics, 41(2), 453-480.
Ffowcs Williams, J. E., & Hawkings, D. L. (1969). Sound generation by turbulence and surfaces in arbitrary motion. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 264(1151), 321-342.
Fluent. (2013). Fluent Acoustics Modeling. Retrieved from https://wenku.baidu.com/view/fa2ab388680203d8ce2f24cb.html?from=search.(Dec.25,2019)
Germano, M.; Piomelli, U.; Moin, P., & Cabot, W. H. (1991). A dynamic subgrid‐scale eddy viscosity model. Physics of Fluids A: Fluid Dynamics, 3(7), 1760-1765.
Holmes, J. R. (2014). Defend the First Island Chain. Retrieved from https://www.usni.org/magazines/proceedings/2014/april/defend-first-island-chain.(Dec.14,2019)
Howard, C. Q. (2011). Recent developments in submarine vibration isolation and noise control. Paper presented at the Proceedings of the 1st Submarine Science Technology and Engineering Conference.
Howe, M. (2004). Mechanism of sound generation by low Mach number flow over a wall cavity. Journal of sound and vibration, 273(1-2), 103-123.
Lafon, P.; Caillaud, S.; Devos, J., & Lambert, C. (2003). Aeroacoustical coupling in a ducted shallow cavity and fluid/structure effects on a steam line. Journal of Fluids and structures, 18(6), 695-713.
Lilly, K. (1966). On the application of the eddy viscosity concept in the inertial sub-range of turbulence.
Lee, Y.-J. (2008). General arrangement of the Agosta Submarine. Retrieved from https://www.researchgate.net/figure/General-arrangement-of-the-U209-1400-Submarine_fig1_270630892.(Dec.14,2019)
Ross, D. (2013). Mechanics of underwater noise: Elsevier.
Rossiter, J. (1964). Wind tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Aeronautical Research Council, Landon.
Smagorinsky, J. (1963). General circulation experiments with the primitive equations: I. The basic experiment. Monthly weather review, 91(3), 99-164.
Team, L. C. (2014). USING CFD TO PREDICT FLOW-GENERATED NOISE AND OTHER AEROACOUSTIC EFFECTS. Retrieved from https://www.computationalfluiddynamics.com.au/using-cfd-to-predict-flow-generated-noise/.(Jun.15,2019)
Narayan, V. (2014). Submarines of the Indian Navy. Retrieved from https://www.team-bhp.com/forum/commercial-vehicles/171872-submarines-indian-navy.html.(Nov.11,2019)
Yousheng, Z. X. W. (2002). Study of similarities for fluid-dynamic noise [J]. Acta Acustica, 4.
馬大猷(2004). 現代聲學理論基礎. 科學出版社.(北京)
安洪偉, & 許忠勇(2008). 潜艇上形形色色的流水孔. 兵器知識(7), 66-68.
李環, 劉聰尉, 吳方良, & 陳燦(2016). 水動力噪聲計算方法總述. 中國艦船研究, 11(2), 72-89.
紀永添(2017). 台灣為何這麼需要潛艦. Retrieved from https://www.upmedia.mg/news_info.php?SerialNo=14151.(Apr.21,2019)
倪大明, 張文平, & 明平劍(2013). 低速湍流中氣動噪聲预測方法. 科技導報, 31(32), 15-19.
崔亮(2014). ANSYS CFD在汽車氣動噪音領域的應用. Retrieved from https://wenku.baidu.com/view/7383e90b767f5acfa1c7cdde.html?from=search&fbclid=IwAR0othW5lzbaVhC5EoYnDvH-yir2qDZYiaOMn7pWGdzj6roNPKqobDAkjeE.(Apr.10,2019)
張超群、陳文川(2013). 汽車噪音與振動問題之故障診斷及排除. Retrieved from https://books.google.com.tw/books?id=WnpFCgAAQBAJ&printsec=frontcover&dq=%E6%B1%BD%E8%BB%8A%E5%99%AA%E9%9F%B3%E8%88%87%E6%8C%AF%E5%8B%95%E5%95%8F%E9%A1%8C%E4%B9%8B%E6%95%85%E9%9A%9C%E8%A8%BA%E6%96%B7%E5%8F%8A%E6%8E%92%E9%99%A4&hl=zh-TW&sa=X&ved=0ahUKEwjygeu9vqblAhXhLqYKHRHtApcQ6AEIKDAA#v=onepage&q=%E6%B1%BD%E8%BB%8A%E5%99%AA%E9%9F%B3%E8%88%87%E6%8C%AF%E5%8B%95%E5%95%8F%E9%A1%8C%E4%B9%8B%E6%95%85%E9%9A%9C%E8%A8%BA%E6%96%B7%E5%8F%8A%E6%8E%92%E9%99%A4&f=false.(Sep.3, 2019)
莊俊雄(1992). 談現代潛艦靜音設計之發展及運用. Retrieved from http://top81.ws/show.php?f=6&t=107130&m=402453.(Sep.3, 2019)
陸磐安(2002). 潛艇概念設計: 成功大學出版中心.(台南)