Application of Fuzzy Logic Technology to Evaluate the Performance of Double-Pontoon-Type BreakwaterApplication of Fuzzy Logic Technology to Evaluate the Performance of Double-Pontoon-Type Breakwater

Mohamed E. El-Naggar(1*)

(1) Civil Engineering Dept., Faculty of Engineering, Alexandria University, Egypt
(*) Corresponding author

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Performance of floating breakwaters is usually evaluated by transmission coefficient, Kt. The prediction of Kt with an acceptable accuracy is a vital issue in the evaluation of the breakwater performance. In this research, experimental works and fuzzy logic methodology are used to investigate the performance of double-pontoon-type floating breakwater. Experimental data are employed to develop the fuzzy logic model. Wave steepness, Hi/L, pontoon depth ratio, di/d, gap width ratio, G/bi, and total pontoon width ratio, B/L were used as fuzzy input data to estimate the corresponding transmission coefficient, Kt. Results of fuzzy logic model showed a quite close estimation with the experimental ones. Parametric studies were conducted to investigate the efficiency of the proposed breakwater type. Results of these parametric studies showed that the breakwater efficiency increases as the wave steepness increases along with the increase of back pontoon draft and/or width. Results also showed that the performance of the system to attenuate the wave energy increased when the back pontoon draft was higher than the front one. The gap between pontoons has also a significant effect on the transmission coefficient. The transmission coefficient improved as the gap width decreases. Finally, a simple empirical formula is developed to estimate the transmission coefficient of regular waves.
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Floating Breakwaters; Fuzzy Logic Model; Pontoon-Type; Wave Transmission

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