Formula to Predict Transmission for -Type Floating Breakwaters
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 139, Issue 1
Abstract
The aim of this paper is to define a simple and useful formula to predict wave transmission for a common type of floating breakwater (FB), supplied with two lateral vertical plates protruding downward, named -type FB. Eight different models, with mass varying from 16 to 76 kg, anchored with chains, have been tested in the wave flume of the Maritime Laboratory of Padova University, under irregular wave conditions. Water elevation in front and behind the structure has been measured with two arrays of four wave gauges. Our starting point for the prediction of wave transmission was the classical relationship established by Macagno in 1954. His relationship was derived for a box-type fixed breakwater assuming irrotational flow. Consequently, he significantly underestimated transmission for short waves and large drafts. This paper proposes an empirical modification of his relationship to properly fit the experimental results and a standardized plotting system of the transmission coefficient, based on a simple nondimensional variable. This variable is the ratio between the peak period of the incident wave and an approximation of the natural period of the heave oscillation. A fairly good accuracy of the prediction is found analyzing the data in the literature relative to variously moored -type FBs, tested in small-scale wave tanks under regular and irregular wave conditions.
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Acknowledgments
The support of the European Union FP7 THESEUS “Innovative technologies for safer European coasts in a changing climate,” contract ENV.2009-1, n. 244104, is gratefully acknowledged.
References
Behzad, M., and Akbari, M. (2007). “Experimental investigation on response and efficiency of moored pontoon type floating breakwaters.” Iranian J. Sci. Technol. Trans. B Eng., 31(1), 95–99.
Blumberg, G. P., and Cox, R. J. (1988). “Floating breakwater physical model testing for marina applications.” World Association for Waterborne Transport Infrastructure (PIANC) Bulletin No. 63, Brussels, Belgium.
Chakrabarti, S. K. (1987). Hydrodynamics of off-shore structures, WIT Press, Southampton, U.K.
Christian, C. D. (2000). “Floating breakwaters for small boat marina protection.” Proc., 27th Int. Conf. on Coastal Engineering (ICCE), World Scientific, 2268–2277.
Cox, R., Coghlan, I., and Kerry, C. (2007). “Floating breakwater performance in irregular waves with particular emphasis on wave transmission and reflection, energy dissipation, motion and restraining forces.” Proc., Coastal Structures, World Scientific, Singapore, 7(1), 351–362.
Diamantoulaki, I., and Angelides, D. C. (2011). “Modeling of cable-moored floating breakwaters connected with hinges.” Eng. Struct., 33(5), 1536–1552.
Dong, G. H., et al. (2008). “Experiments on wave transmission coefficients of floating breakwaters.” Ocean Eng., 35(8–9), 931–938.
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), 33–41.
Gesraha, M. R. (2006). “Analysis of Π shaped floating breakwater in oblique waves: I. Impervious rigid wave boards.” Appl. Ocean Res., 28(5), 327–338.
Hales, L. Z. (1981). “Floating breakwaters: State-of-the-art literature review.” Technical Rep. TR81-1. United States Army Corps of Engineers, Springfield, VA.
Jones, D. B. (1971). “Transportable breakwaters—A survey of concepts.” Technical Rep. R727, Naval Civil Engineering Laboratory, Port Hueneme, CA.
Koftis, T. H., Prinos, P., and Koutandos, E. (2006). “2D-V hydrodynamics of wave–floating breakwater interaction.” J. Hydraul. Res., 44(4), 451–469.
Koutandos, E., Prinos, P., and Gironella, X. (2005). “Floating breakwaters under regular and irregular wave forcing-reflection and transmission characteristics.” J. Hydraul. Res., 43(2), 174–188.
Loukogeorgaki, E., and Angelides, D. C. (2005). “Stiffness of mooring lines and performance of floating breakwaters in three dimensions.” Appl. Ocean Res., 27(4–5), 187–208.
Loukogeorgaki, E., and Angelides, D. C. (2009). “Status identification and optimum adjustment of performance of moored floating breakwaters.” Int. J. of Offshore Polar Eng., 19(1), 31–41.
Macagno, E. O. (1954). “Houle dans un canal présentant un passage en charge.” La Houille Blanche, 1(1), 10–37 (in French).
Mansard, E. P. D., and Funke, E. R. (1980). “The measurement of incident and reflected spectra using a least squares method.” Proc., 17th Int. Conf. Coastal Eng., ASCE, Reston, VA, 154–172.
Martinelli, L., and Ruol, P. (2006). “2D model of floating breakwater dynamics under linear and nonlinear waves.” Proc., 2nd COMSOL User Conf., COMSOL, Milan, Italy.
Martinelli, L., Ruol, P., and Zanuttigh, B. (2008). “Wave basin experiments on floating breakwaters with different layouts.” Appl. Ocean Res., 30(3), 199–207.
Mays, T. W. (1997). “Three-dimensional analysis of moored cylinders used as breakwaters.” M.S. thesis, Virginia Polytechnic Institute and State Univ., Blacksburg, VA.
Neelamani, S., and Rajendran, R. (2002). “Wave interaction with T-type breakwaters.” Ocean Eng., 29(2), 151–175.
Newman, J. N. (1977). Marine hydrodynamics, MIT Press, Cambridge, MA.
Oliver, J. G., et al. (1994). “Floating breakwaters—A practical guide for design and construction.” Rep. No. 13, World Association for Waterborne Transport Infrastructure (PIANC), Brussels, Belgium.
Ozeren, Y., Wren, D. G., Altinakar, M., and Work, P. A. (2011). “Experimental investigation of cylindrical floating breakwater performance with various mooring configurations.” J. Waterway, Port, Coastal, Ocean Eng., 137(6), 300–309.
Peña, E., Ferreras, J., and Sanchez-Tembleque, F. (2011). “Experimental study on wave transmission coefficient, mooring lines and module connector forces with different designs of floating breakwaters.” Ocean Eng., 38(10), 1150–1160.
Rahman, M. A., Mizutani, N., and Kawasaki, K. (2006). “Numerical modeling of dynamic responses and mooring forces of submerged floating breakwater.” Coast. Eng., 53(10), 799–815.
Ruol, P., and Martinelli, L. (2007). “Wave flume investigation on different mooring systems for floating breakwaters.” Proc., Coast. Struct., 7(1), 327–338.
Ruol, P., Martinelli, L., and Pezzutto, P. (2011). “Multi-chamber OWC devices to reduce and convert wave energy in harbour entrance and inner channels.” Proc., Int. Offshore and Polar Engineering Conf., Maui, HI, Vol. 1, 622–629.
Ruol, P., Martinelli, L., and Zanuttigh, B. (2008). “2D and 3D experimental analysis on forces and performance of floating breakwaters.” Proc., 2nd Int. Conf. Application of Physical Modelling to Port and Coastal Protection (CoastLab), International Association of Hydraulic Engineering and Research (IAHR), Bari, Italy, 557–572.
Ruol, P., Pezzutto, P., and Martinelli, L. (2010). “Analisi sperimentale sulla risposta 2D di molteplici frangiflutti galleggianti.” Proc., XXXII Convegno di Idraulica e Costruzioni Idrauliche (IDRA), Walter Farina IT, Palermo, Italy (in Italian).
Sarpkaya, T., and Isaacson, M. (1981). Mechanics of wave forces on offshore structures, Van Nostrand-Reinhold, New York.
Senjanovic, I., Malenica, S., and Tomasevic, S. (2008). “Investigation of ship hydroelasticity.” Ocean Eng., 35(5–6), 523–535.
THESEUS. (2012). “Innovative technologies for safer European coasts in a changing climate.” 〈http://www.theseusproject.eu〉 (Jan. 1, 2012).
Tolba, E. R. A. S. (1998). “Behaviour of floating breakwaters under wave action.” Ph.D. thesis, Suez Canal Univ., Port Said, Egypt.
Ursell, F. (1947). “The effect of a fixed vertical barrier on surface waves in deep water.” Math Proc., Cambridge Philos. Soc., 43(3), 374–382.
Wiegel, R. L. (1960). “Transmission of waves past a rigid vertical thin barrier.” J. Waterway, Port, Coastal, Ocean Eng., 86(1), 1–12.
Zelt, J. A., and Skjelbreia, J. (1992). “Estimating incident and reflected wave fields using an arbitrary number of wave gauges.” Proc., 23rd Int. Conf. Coastal Engineering (ICCE), ASCE, Vol. 1, Reston, VA, 777–789.
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Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 139 • Issue 1 • January 2013
Pages: 1 - 8
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Sep 12, 2011
Accepted: Mar 15, 2012
Published online: Mar 19, 2012
Published in print: Jan 1, 2013
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