跳到主要內容

臺灣博碩士論文加值系統

(3.235.56.11) 您好!臺灣時間:2021/07/29 10:03
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

: 
twitterline
研究生:陳德著
研究生(外文):Tran Duc Tru
論文名稱:翼版對浮式結構物特性影響之分析研究
論文名稱(外文):Hydrodynamic Analysis of Floating Structures Characteristics with Skirts
指導教授:翁文凱翁文凱引用關係石瑞祥石瑞祥引用關係
指導教授(外文):Wen-Kai WengRuey-Syan Shih
口試委員:陳文俊岳景雲李兆芳邱永芳許泰文李忠潘
口試日期:2016-06-06
學位類別:博士
校院名稱:國立臺灣海洋大學
系所名稱:河海工程學系
學門:工程學門
學類:河海工程學類
論文種類:學術論文
論文出版年:2016
畢業學年度:104
語文別:英文
論文頁數:80
中文關鍵詞:浮式結構物對偶邊界元素法翼板反應振幅運算子柔性
外文關鍵詞:Floating structureBoundary Element Methodrigid skirtresponse amplitude operatorsFlexible
相關次數:
  • 被引用被引用:0
  • 點閱點閱:63
  • 評分評分:
  • 下載下載:15
  • 收藏至我的研究室書目清單書目收藏:0
本研究利用對偶邊界元素法(Dual Boundary Element Method , DBEM)建立一個數值模式來模擬設有翼板及繫纜浮體的運動行為,包括:前後移動、垂直移動、縱轉、波浪反射率、透射係數、繫留力及能量損失。
從結果發現,在矩形浮體下方加裝兩個翼板,可以增加浮體的附加質量,在波浪作用時給浮體結構物一個緩衝的作用力,因此浮體較容易受長週期波影響。這些現象增加了浮體對抗波浪的能力。本研究翼板和垂直軸的夾角設計為(00、300、600、900),當翼板角度為0度時,反應振福運算子(Response Amplitude Operators , RAO)呈現出來的模擬結果跟Mohamed R. Gesraha的結果吻合;所計算出來的結果也跟實驗數據相近。另外,本篇論文亦有討論拖曳係數C¬¬¬¬¬d¬ 、翼板數量及翼板的長度。當長週期波通過設有較長翼板的浮體結構物時會產生共振。
另一方面,本文也專注在柔性翼板的研究,包括:結構物的運動模式、繫纜力、透過係數及反射係數。假設浮式結構物在水面上的變化是微小而且線性的,加裝在浮體下方的柔性翼板厚度可以忽略並且為均勻抗彎。本文在此選擇四種彈性模數進行討論,分別為 = 0.001, 0.05, 0.5 和 5。結果顯示當柔性翼板的彈性模數逐漸減少時,浮體震盪的自然頻率、繫留力、波浪反射力和波浪繞射情況會落在短週期波的區間內。此外,本研究也發現浮體結構物的繫留力和垂直運動有正相關。

In this study, the Dual Boundary Element Method (DBEM) has been applied to numerical simulations of the dynamic behavior of floating bodies with rigid skirt and mooring lines such as: pitch RAO (response amplitude operators), surge RAO and heave RAO; reflection and transmission coefficients; forces on mooring lines, and energy loss.
The results show that the double skirts mounted beneath a rectangular floating structure, which together comprise a floating structure, can increase the added mass and thus cause the response of the floating structure to be less sensitive, thus the floating structure can only be excited by waves of a longer period waves. Such phenomenon enhances the ability of the floating structure to resist the wave forces. The angles between the rigid skirts and the vertical axis of the wave tank varied from 00 to 900 with 300 degree difference between two adjacent designs. When the angle is 00 degrees, the numerical results of the response amplitude operators agree well with the results done by Mohamed R. Gesraha. In other cases, the calculated results also agree well with the experimental data. The drag coefficient C¬¬¬¬¬d¬ also is reported and discussed in this study. The number of rigid skirts and the length of the rigid skirts also are considered in this research. The resonant frequency of the floating structure with longer rigid skirts corresponds with the long wave period.
On the other hand, this study focused on the change in the structure’s motion in each mode; forces on the mooring lines; transmission and reflection coefficients induced by the flexible rigidity. The motions of the structure were assumed to be small and linear. The flexible skirts mounted beneath the structure were assumed to be of uniform flexural rigidity and the thickness of the skirts was negligible. The flexible rigidities selected were 0.001, 0.05, 0.5 and 5 for simulation. The results show that the natural frequencies of the structure’s oscillation, moored force, wave reflection and transmission tended to the region of short-period waves when the flexible rigidity gradually decreases. Positive correlation exists between the aft mooring force and the pitch motion of the floating structure.

Acknowledgements I
摘要 III
Abstract IV
List of Figures VII
List of Tables XI
List of Abbreviations XII
Chapter 1 Introduction 1
1.1 Research motivation 1
1.2 Literature review 2
1.3 Research tools 5
1.4 Dissertation outline 5
Chapter 2 Theoretical formulations of the floating structure with rigid skirts 6
2.1 Theoretical analysis 6
2.2 Potential function in region I and III 7
2.3 Dual boundary element method 8
2.4 Boundary conditions of region II 10
2.5 The coefficients of reflection and transmission 14
2.6 Responses of the floating structure 15
2.7 Matrix form of the equation 17
Chapter 3 Analysis of a moored floating structure with flexible skirts 19
3.1 Problem definition 19
3.2 Boundary condition on the flexible skirts 20
3.3 Flexible skirts boundary 20
3.4 Equation of the floating structure’s motions 26
3.5 Floating structure boundary condition 27
3.6 Forces on mooring lines 28
3.7 Summary 29
Chapter 4 The experimental setup and data analysis 30
4.1 Two-dimensional wave tank 30
4.2 Two-dimensional experimental setup 32
4.3 Data analysis 33
Chapter 5 Results and discussion of the floating structure with rigid skirts 35
5.1 Verification of numerical model in free body with vertical skirts 35
5.2 Effects of the floating structures with different length of rigid skirts on motion and wave reflection and transmission 36
5.3 Effects of the floating structures with a different number of rigid skirts on motion and wave reflection and transmission coefficient 39
5.4 Effects of the floating structures with different drag coefficients and skirts angle 43
5.4.1 Effects of the floating structures on Heave RAO, Pitch RAO, and Surge RAO 43
5.4.2 Effects of reflection and transmission 49
5.4.3 Effects of energy loss 54
5.5 Effects of rigid skirts and L shaped rigid skirts 56
5.5 Comparison between the floating structure and the floating structure with and without rigid skirts 60
Chapter 6 Results and discussion of the moored floating structure with flexible skirts 64
6.1 Influence of flexible rigid skirts on structure’s motion 64
6.2 The wave reflection and transmission coefficients 66
6.3 The influences of mooring line forces 68
Chapter 7 Conclusion 70
References 72


Abul-Azm, A. G., & Gesraha, M. R. (2000). Approximation to the hydrodynamics of floating pontoons under oblique waves. Ocean Engineering, 27(4), 365-384.
Beck, R. F. (1994). Time-domain computations for floating bodies. Applied Ocean Research, 16(5), 267-282.
Black, J. L., Mei, C. C., & Bray, M. C. G. (1971). Radiation and scattering of water waves by rigid bodies. J. Fluid Mech, 46(1), 151-164.
Briggs, M. J. (2001). Analytical and numerical models of the RIBS XM99 ocean-scale prototype: DTIC Document.
Chakrabarti, S. K. (1994). Hydrodynamics of offshore structures: Computational mechanics Publications, Springer-Verlag.
Chen, J. T., & Hong, H. K. (1983). Boundary Element Method: Taipei: New-World. (in Chinese)
Clough, R. W., & Penzien, J. (1993). Dynamics of structures: McGraw-Hill, New York.
Contento, G., & Casole, S. (1995). On the generation and propagation of waves in 2D numerical wave tanks. Proceedings of the Fifth (1995) International Offshore and Polar Engineering Conderence, III, 10-18.
Dalrymple, R. A., & Dean, R. G. (1984). Water wave mechanics for engineers and scientists: Prentice Hall.
Drimer, N., Agnon, Y., & Stiassnie, M. (1992). A simplified analytical model for a floating breakwater in water of finite depth. Applied Ocean Research, 14(1), 33-41.
Gesraha, M. R. (2006). Analysis of Π shaped floating breakwater in oblique waves: I. Impervious rigid wave boards. Applied Ocean Research, 28(5), 327-338.
Goda, Y., & Suzuki, T. (1976). Estimation of incident and reflected waves in random wave experiments. Coastal Engineering Proceedings, 1(15).
Hieu, P. D., & Tanimoto, K. (2006). Verification of a VOF-based two-phase flow model for wave breaking and wave–structure interactions. Ocean Engineering, 33(11), 1565-1588.
Huang, C.-C., & Tang, H.-J. (2009). Dynamic Responses of Moored Floating Dual Pontoon Structure in a Fully Nonlinear Numerical Wave Tank. Proceedings of the Nineteenth (2009) International Offshore and Polar Engineering Conderence. Osake, Japan, 414-421.
Hudspeth, R., Nakamura, T., & Pyun, C.-K. (1994). Convergence criteria for axisymmetric Green's function with application to floating bodies. Ocean Engineering, 21(4), 381-400.
Isaacson, M., & Byres, R. (1988). Floating breakwater response to wave action. Coastal Engineering Proceedings, 1(21), 2189-2200.
Isaacson, M., Ng, J. Y., & Cheung, K. F. (1993). Second-order wave radiation of three-dimensional bodies by time-domain method. International Journal of Offshore and Polar Engineering, 3(4), 264-272.
Karim, M. F., Tanimoto, K., & Hieu, P. D. (2004). Simulation of wave transformation in vertical permeable structure. International Journal of Offshore and Polar Engineering, 14(02).
Kashiwagi, M. (2005). Wave-induced motions of a body floating in a two-layer fluid. Paper presented at the Proceedings of The Fiffteenth (2005) International Offshore and Polar Engineering Conference, Seoul, Korea.
Kashiwagi, M., Inada, M., & Momoda, T. (1998). A time-domain nonlinear simulation method for wave-induced motions of a floating body. Journal of the Society of Naval Architects of Japan, 184, 139-148.
Ker, W.-K., & Lee, C.-P. (2002). Interaction of waves and a porous tension leg platform. Journal of waterway, port, coastal, and ocean engineering, 128(2), 88-95.
Lee, C.-P. (1994). Dragged surge motion of a tension leg structure. Ocean Engineering, 21(3), 311-328.
Lee, C.-P., & Ker, W.-K. (2002). Coupling of linear waves and a hybrid porous TLP. Ocean Engineering, 29(9), 1049-1066.
Lee, C.-P., & Lee, J.-F. (1993). Wave-induced surge motion of a tension leg structure. Ocean Engineering, 20(2), 171-186.
Lee, H. H., Wang, P.-W., & Lee, C.-P. (1999). Dragged surge motion of tension leg platforms and strained elastic tethers. Ocean Engineering, 26(6), 575-594.
Lee, J.-F. (1988). Theoretical analysis of wave interaction with flexible breakwater. Paper presented at the Proc. 10th Conf. on Ocean Engineering in Republic of China.
Lee, J.-F. (1995). On the heave radiation of a rectangular structure. Ocean Engineering, 22(1), 19-34.
Lee, J., & Cho, W. (2003). Hydrodynamic analysis of wave interactions with a moored floating breakwater using the element-free Galerkin method. Canadian Journal of Civil Engineering, 30(4), 720-733.
Leonard, J. W., Huang, M.-C., & Hudspeth, R. T. (1983). Hydrodynamic interference between floating cylinders in oblique seas. Applied Ocean Research, 5(3), 158-166.
Li, Y., & Lin, M. (2012). Regular and irregular wave impacts on floating body. Ocean Engineering, 42, 93-101.
Liu, X., & Sakai, S. (2000). Nonlinear analysis on the interaction of waves and flexible floating structure. Paper presented at the Proceedings of the Tenth (2000) International Offshore and Polar Engineering Conference.
Lu, L., Teng, B., Sun, L., & Chen, B. (2011). Modelling of multi-bodies in close proximity under water waves-Fluid forces on floating bodies. Ocean Engineering, 38(13), 1403-1416.
McCartney, B. L. (1985). Floating breakwater design. Journal of waterway, port, coastal, and ocean engineering, 111(2), 304-318.
McIver, P. (1986). Wave forces on adjacent floating bridges. Applied Ocean Research, 8(2), 67-75.
Mei, C. C. (1989). The applied dynamics of ocean surface waves. Volume 1 of Advanced Series on Ocean Engineering: World Scientific.
Murali, K., & Mani, J. (1997). Performance of cage floating breakwater. Journal of waterway, port, coastal, and ocean engineering, 123(4), 172-179.
Nakayama, T., & Washizu, K. (1980). Nonlinear analysis of liquid motion in a container subjected to forced pitching oscillation. International Journal for Numerical Methods in Engineering, 15(8), 1207-1220.
Sakakiyama, T., & Kajima, R. (1992). Numerical simulation of nonlinear wave interacting with permeable breakwaters. Paper presented at the Proceedings of the 23rd International Conference on Coastal Engineering, ASCE.
Sannasiraj, S., Sundar, V., & Sundaravadivelu, R. (1998). Mooring forces and motion responses of pontoon-type floating breakwaters. Ocean Engineering, 25(1), 27-48.
Sannasiraj, S., Sundaravadivelu, R., & Sundar, V. (2000). Diffraction–radiation of multiple floating structures in directional waves. Ocean Engineering, 28(2), 201-234.
Sen, D. (1993). Numerical simulation of motions of two-dimensional floating bodies. Journal of Ship Research, 37(4), 307-330.
Tanizawa, K. (1995). A nonlinear simulation method of 3-D body motions in waves. Journal of the Society of Naval Architects of Japan, 178, 179-191.
Tanizawa, K. (1996). Long time fully nonlinear simulation of floating body motions with artificial damping zone. Journal of the Society of Naval Architects of Japan, 180, 311-320.
Tanizawa, K., & Naito, S. (1999). An application of fully nonlinear numerical wave tank to the study of chaotic roll motions. International Journal of Offshore and Polar Engineering, 9(2), 90-96.
Wang, H.-Y., & Sun, Z.-C. (2010). Experimental study on the influence of geometrical configuration of porous floating breakwater on performance. Journal of Marine Science and Technology, 18(4), 574-579.
Wang, K.-H., & Ren, X. (1993). Water waves on flexible and porous breakwaters. Journal of Engineering Mechanics, 119(5), 1025-1047.
Weng, W.-K., & Chou, C.-R. (2007). Analysis of responses of floating dual pontoon structure. China Ocean Engineering, 21(1), 91-104.
Williams, A., Geiger, P., & McDougal, W. (1991). Flexible floating breakwater. Journal of waterway, port, coastal, and ocean engineering, 117(5), 429-450.
Williams, A., Geiger, P., & McDougal, W. (1992). A submerged compliant breakwater. Journal of Offshore Mechanics and Arctic Engineering, 114(2), 83-90.
Williams, A., & McDougal, W. (1996). A dynamic submerged breakwater. Journal of waterway, port, coastal, and ocean engineering, 122(6), 288-296.
Williams, A., Lee, H., & Huang, Z. (2000). Floating pontoon breakwaters. Ocean Engineering, 27(3), 221-240.



連結至畢業學校之論文網頁點我開啟連結
註: 此連結為研究生畢業學校所提供,不一定有電子全文可供下載,若連結有誤,請點選上方之〝勘誤回報〞功能,我們會盡快修正,謝謝!
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top