Hydrodynamic Performance of H-shaped Pile-restrained Floating Breakwater Integrated with Horizontal Plates

Abstract

This study analyzes the hydrodynamic performance of an H-shaped pile-restrained composite breakwater integrated with a pair of horizontal plates placed on the seaside and the leeside of the breakwater. The wave interaction with the H-shaped breakwater is examined by analyzing the wave reflection, transmission, and dissipation coefficients. Additionally, the horizontal wave force coefficients are evaluated to analyze the effectiveness of the horizontal plates when integrated with the main structure. The primary structural parameters directly affect the performance of the composite breakwater and are varied within the feasible range of nondimensional wave numbers, relative spacings, and incident wave angles. This study presents a comparative analysis of the arrangement of the horizontal plates in terms of spacing and inclinations inward and outward to the breakwater using a multidomain boundary element method (BEM). The variation of the structural parameters proposes suitable dimensions for integrated H-shaped breakwater with horizontal plates that provide optimal performance in shallow and deep-water regions. The optimum plate porosity, dimensions of the H-shaped structure, inclinations, and spacing between the plate and breakwater are thoroughly discussed. This study shows that impermeable plates are the excellent means to control the wave force in the intermediate water depth regions than in deep-water regions at resisting wave force. The wave force coefficient on the breakwater is significantly larger than that on the seaside plates. Interestingly, inward-inclined plates perform most efficiently at angles greater than 5°, except in deep-water regions where horizontal plates perform better. In addition, this study noted that regardless of water depth, the outward-inclined plates are the least effective in reflecting the incident wave energy. This study will help plan the layout of suitable composite structures for efficient near-shore and offshore harbor protection according to the site criteria and environmental conditions.

Keywords

Composite breakwater / Horizontal plates / Reflection and transmission coefficients / Multidomain boundary element method (Multidomain BEM) / Wave force coefficient

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