Wave transmission model over hexagonal artificial reefs using DualSPHysics

Abstract

The functions and uses of artificial reefs have evolved from a method of coral reefs restoration to a coastal protection system. The artificial reef can reduce the hydraulic load on the coast to the level required to maintain shoreline balance. Various materials and shapes of artificial reefs have been introduced. This paper discussed the wave transmission over the hexagonal-shaped artificial reef with six holes on each side. The study was conducted using the Smoothed Particle Hydrodynamic (SPH) method integrated into DualSPHysics software to see the effect of gaps between structures with a predetermined configuration on the value of the transmission coefficient (Kt). It was found that the arrangement with no gap could absorb waves better than the configuration with a gap of 0.15 m and 0.112 m based on the Kt value obtained. In terms of hydrodynamics, it was found that: (1) The increment of the wave steepness, the smaller the Kt value obtained, (2) The larger the wave height, the smaller the Kt value at 0.1 m freeboard depth. However, on the freeboard with a depth of 0.2 m and 0.3 m, it was found that the greater the wave height, the greater the Kt value, (3) the increment of the wave period, the Kt was higher, and also (4) the higher the freeboard, the higher the Kt values.