Numerical investigation on wave transmission characteristics of perforated and non-perforated pile breakwater

Abstract

Dock operations, harbouring and many other port activities demand tranquil water condition. This makes breakwater structures more than essential in coastal engineering applications. For zero wave action, rubble mound or vertical wall breakwaters are used, and for small docks and shores, piles can be used as efficient breakwaters. The permeability of pile breakwaters also aides in keeping the shores clean as there is water circulation and keeps the interferences caused due to littoral drift to the minimum. Numerical study on the single row pile breakwater is carried out using an open source computational fluid dynamics (CFD) software REEF3D. Interaction of waves with non-porous pile breakwater is simulated in a three-dimensional numerical wave tank using REEF3D and resulted transmission coefficient is validated using the physical model studies as reported by Subba Rao et al. (1999). Further, the efficiency of porous piles over non-porous piles is studied by simulating wave conditions by varying wave height, wave period, water depth and percentage porosity of the piles. It has been observed from the present study that porous piles are more efficient in wave attenuation compared to non-porous piles. The reason is that perforations increase turbulence during wave interaction which results in a better wave attenuation.