0
Research Papers: Offshore Technology

Experimental Study on the Hydrodynamic Performance of Floating Pontoon Type Breakwater With Skirt Walls

[+] Author and Article Information
S. Neelamani

Coastal Management Program,
Environment and Life Sciences Research Center,
Kuwait Institute for Scientific Research,
P.O. Box 24885,
Safat 13109, Kuwait
e-mail: nsubram@kisr.edu.kw

Josko Ljubic

Coastal Management Program,
Environment and Life Sciences Research Center,
Kuwait Institute for Scientific Research,
P.O. Box 24885,
Safat 13109, Kuwait
e-mail: jljubic@kisr.edu.kw

Contributed by the Ocean, Offshore, and Arctic Engineering Division of ASME for publication in the JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING. Manuscript received March 2, 2017; final manuscript received September 27, 2017; published online November 16, 2017. Assoc. Editor: Theodoro Antoun Netto.

J. Offshore Mech. Arct. Eng 140(2), 021303 (Nov 16, 2017) (9 pages) Paper No: OMAE-17-1029; doi: 10.1115/1.4038343 History: Received March 02, 2017; Revised September 27, 2017

Floating breakwaters (FBWs) are widely used in moderate wave climatic conditions for coastal protection against erosion and for wave reduction around offshore loading terminals and open ocean construction sites. Literature shows that the width of a pontoon-type FBW is about 50% of the incident wavelength in order to achieve 50% wave height reduction at the lee side of the FBW. Hence, for a typical wavelength of 40 m, the width needed for pontoon FBW is about 20 m. Such an FBW may not be cost competitive. Is it possible to reduce the width of the pontoon FBW significantly by adding skirt walls (single, twin, triple, or five) at its keel. What will be the effect on mooring forces? In order to find solutions for these problems, experimental investigations were carried out on a typical pontoon-type FBW as well as pontoon with skirt walls. Both opaque and porous skirt walls were used. Wave transmission, reflection, and mooring forces, both on the sea side and lee side, were measured. It was found from this study that it is possible to reduce the width by 20 to 40% by introducing three or five skirt walls. However, introducing skirt walls increased the mooring forces by 10 to 30%. The results of this study are expected to be useful for cost-effective design of FBWs.

Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Yamamoto, T. , Yoshida, A. , and Ijima, T. , 1980, “ Dynamics of Elastically Moored Floating Objects,” Appl. Ocean Res., 2(2), pp. 85–92. [CrossRef]
Stiassnie, M. , 1980, “ A Simple Mathematical Model of a Floating Breakwater,” Appl. Ocean Res., 2(3), pp. 107–111. [CrossRef]
Yamamoto, T. , 1981, “ Moored Floating Breakwater Response to Regular and Irregular Waves,” Appl. Ocean Res., 3(1), pp. 27–36. [CrossRef]
Hanif, M. , 1983, “ Analysis of Heaving and Swaying Motion of a Floating Breakwater by Finite Element Method,” Ocean Eng., 10(3), pp. 181–190. [CrossRef]
Georgiadis, C. , 1983, “ CGFLOAT (a Computer Program for the Dynamic Analysis of Floating Bridges and Breakwaters),” Adv. Eng. Software, 5(4), pp. 215–220. [CrossRef]
Leach, P. A. , McDougal, W. G. , and Sollitt, C. K. , 1985, “ Hinged Floating Breakwater,” J. Waterw., Port, Coastal, Ocean Eng., 111(5), pp. 895–909. [CrossRef]
Williams, A. N. , 1985, “ Wave Diffraction by Elliptical Breakwaters in Shallow Water,” Ocean Eng., 12(1), pp. 25–43. [CrossRef]
Drimer, N. , Agnon, Y. , and Stiassnie, M. , 1992, “ A Simplified Analytical Model for a Floating Breakwater in Water of Finite Depth,” Appl. Ocean Res., 14(1), pp. 33–41. [CrossRef]
Abul-Azm, A. G. , 1994, “ Wave Diffraction by Double Flexible Breakwaters,” Appl. Ocean Res., 16(2), pp. 87–99. [CrossRef]
Abul-Azm, A. G. , 1996, “ Wave Diffraction Through Submerged Flexible Breakwaters,” Ocean Eng., 23(5), pp. 403–422. [CrossRef]
Ren, X. , and Wang, K. H. , 1994, “ Mooring Lines Connected to Floating Porous Breakwaters,” Int. J. Eng. Sci., 32(10), pp. 1511–1530. [CrossRef]
Lee, C. P. , and Ker, W. K. , 2002, “ Coupling of Linear Waves and a Hybrid Porous TLP,” Ocean Eng., 29(9), pp. 1049–1066. [CrossRef]
Stiassnie, M. , and Drimer, N. , 2003, “ On a Freely Floating Porous Box in Shallow Water Waves,” Appl. Ocean Res., 25(5), pp. 263–268. [CrossRef]
Gesraha, M. R. , 2006, “ Analysis of Π Shaped Floating Breakwater in Oblique Waves—I: Impervious Rigid Wave Boards,” Appl. Ocean Res., 28(5), pp. 327–338. [CrossRef]
Rahman, M. A. , Mizutani, N. , and Kawasaki, K. , 2006, “ Numerical Modeling of Dynamic Responses and Mooring Forces of Submerged Floating Breakwater,” Coastal Eng., 53(10), pp. 799–815. [CrossRef]
Arunachalam, V. M. , and Raman, H. , 1982, “ Experimental Studies on a Perforated Horizontal Floating Plate Breakwater,” Ocean Eng., 9(1), pp. 35–45. [CrossRef]
McCartney, B. L. , 1985, “ Floating Breakwater Design,” J. Waterw., Port, Coastal, Ocean Eng., 111(2), pp. 304–318. [CrossRef]
Murali, K. , and Mani, J. S. , 1997, “ Performance of Cage Floating Breakwater,” J. Waterw., Port, Coastal, Ocean Eng., 123(4), pp. 172–179. [CrossRef]
Rapaka, E. V. , Natarajan, R. , and Neelamani, S. , 2004, “ Experimental Investigation on the Dynamic Response of a Moored Wave Energy Device Under Regular Sea Waves,” Ocean Eng., 31(5–6), pp. 725–743. [CrossRef]
Günaydin, K. , and Kabdaşli, M. S. , 2007, “ Investigation of Π-Type Breakwaters Performance Under Regular and Irregular Waves,” Ocean Eng., 34(7), pp. 1028–1043. [CrossRef]
Elchahal, G. , Younes, R. , and Lafon, P. , 2008, “ The Effects of Reflection Coefficient of the Harbor Sidewall on the Performance of Floating Breakwaters,” Ocean Eng., 35(11–12), pp. 1102–1112. [CrossRef]
Danish Hydraulic Institute, 2004, “ Wave Synthesizer Software,” Danish Hydraulic Institute, Hørsholm, Denmark.
Neelamani, S. , Al-Banaa, K. , Al-Shatti, F. , Al-Khaldi, M. , and Ljubic, J. , 2013, “ Development of a Feasible Prototype Floating Breakwater for Kuwaiti Marine Conditions,” Kuwait Institute for Scientific Research, Shuwaikh, Kuwait, Final Report No. KISR 11669.

Figures

Grahic Jump Location
Fig. 1

A typical floating pontoon breakwater with five skirt walls added to the keel of the pontoon

Grahic Jump Location
Fig. 2

FBW with five porous skirt walls (configuration 28)

Grahic Jump Location
Fig. 3

Experimental setup

Grahic Jump Location
Fig. 4

Mooring line details

Grahic Jump Location
Fig. 5

Effect of the FBW configuration on Kts, Krs, and Kls for W/Lp = 0.646 with His/d = 0.214

Grahic Jump Location
Fig. 6

Effect of the FBW configuration on Kts, Krs, and Kls for W/Lp = 0.133 with His/d = 0.214

Grahic Jump Location
Fig. 7

Normalized mooring forces on the FBW for different embodiments for W/Lp = 0.646 and His/d = 0.214

Grahic Jump Location
Fig. 8

Normalized mooring forces on the FBW for different embodiments for W/Lp = 0.133 and His/d = 0.214

Grahic Jump Location
Fig. 9

Normalized heave and sway on the FBW for different embodiments for W/Lp = 0.646 and His/d = 0.214

Grahic Jump Location
Fig. 10

Normalized roll on the FBW for different embodiments for W/Lp = 0.646 and His/d = 0.214

Grahic Jump Location
Fig. 11

Normalized heave and sway on the FBW for different embodiment for W/Lp = 0.133 and His/d = 0.214

Grahic Jump Location
Fig. 12

Normalized roll on the FBW for different embodiment for W/Lp = 0.133 and His/d = 0.214

Grahic Jump Location
Fig. 13

FBW width required for Kts = 0.5, 0.4, and 0.3 for a typical design wavelength of 40 m in a random wave field

Grahic Jump Location
Fig. 14

Natural period of oscillations in heave

Grahic Jump Location
Fig. 15

Natural period of oscillations in roll

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In