Chun, I., Min, Y., Ha, D. and Park, K., 2013. A General Purpose Numerical Tool for Determining Wave Control Capability of Perforated Coastal Structures

Perforated breakwaters or seawalls have been installed as structures to maintain water surface tranquility inside or outside harbors by suppressing wave reflection or overtopping. In addition, they can also reduce the impact of wave-breaking forces acting on the structure, ultimately increasing its structural stability. Recently, they have been often employed as transmissive structures that facilitate sea water exchange between the inside and outside harbors. Here, analytical and experimental studies were performed to establish a numerical tool for predicting the wave control characteristics of general perforated coastal structures under regular wave conditions. The numerical analysis, which is based on a boundary element method, was established to calculate wave reflection and transmission coefficients as well as wave pressures and forces acting on various perforated wall structures. This analysis could also accommodate any length of curtain and sill above and below the perforated walls, depth variations among wave chambers, porous materials filling the wave chambers, etc. The friction factor on the perforated walls was revealed in the analysis by an experimental formula extracted from a separate hydraulic experiment. In addition, the nonlinear frictional loss through the perforated wall was determined through an iterative calculation procedure. Hydraulic experiments were also carried out for several types of perforated wall structures, and their results were in good agreement with the numerical values. In addition, the numerical tool was also applied to experimental conditions identical to those of existing studies on perforated wall structures. These results also showed good agreement between experimental and numerical values. Finally, a user-friendly computer program was developed to facilitate the design practice of perforated structures.