Performance assessment of corrugated semi-circular breakwaters for coastal protection

Abstract

The importance of coastal protection increases with the increase in coastal development. Soft and hard protection measures are the most used techniques; however, hard structures are still preferable. Hard structures are characterized by a long lifetime and high stability in rough sea states. Many innovative, environmentally friendly hard coastal protections measured have been proposed and used for specific applications. This research’s main objective is to develop and check a new coastal structure, Corrugated Semi-circular Breakwater (CBW). This structure is modified from the Semi-circular Breakwater (SCBW), one of the hard protections used in Japan and China, to increase its efficiency in coastal protection and electricity generation. A comparative study between CBW and SCBW is carried out physically in a two dimensions wide wave flume with dimensions 1.2*1.2*40 m and numerically using the Flow-3D model. The study checked the effect of the structures in merged, semi-merged, and submerged conditions and increased structure permeability. The reflection, transmission, and dissipation coefficients are used as the efficiency indicators. The results show that CBW is more efficient in wave dissipation, current velocity reductions, and bed stability than SCBW. It is recommended to use the CBW as a submerged protected structure within the recreational coastal areas.

Keywords

• Semi-circular breakwater
• Corrugated semi-circular breakwater
• Wave flume
• Computational fluid dynamics
• Flow-3D
• Velocity distribution