Author(s): Shu Kai Ng; Yuma Ishiduka; Tatsuhiko Uchida; Yuki Kajikawa And Masamitsu Kuroiwa

Linked Author(s): Shu Kai Ng

Keywords: Fluid-structure interaction; 3DC; SPH; Wave height; Detached breakwaters; Bottom velocity

Abstract: Coastal erosion and sediment transport are critical for shoreline stability and infrastructure protection. Offshore breakwaters are widely used to mitigate wave energy and manage sediment dynamics, but they can significantly alter natural patterns of wave behaviour and sediment transport. This study investigates the influence of detached breakwaters on wave height and bottom velocity using a combination of experimental and numerical approaches. Experiments were conducted in a wave flume for measuring wave height and bottom velocity at specific points, with numerical simulations using three-dimensional calculation models with the Eulerian approach (3DC) and the Lagrangian approach of Smoothed Particle Hydrodynamics (SPH). The results revealed that both numerical models demonstrated good agreement in capturing initial wave characteristics and dominant frequencies while reflected waves and complex wave patterns were inadequately represented. Comparisons of bottom velocity showed that both models reasonably simulated circulation patterns behind breakwaters, though 3DC exhibited a stronger seaward flow convergence. These findings underscore the complementary nature of experimental and numerical approaches in understanding wave dynamics and their implications for coastal engineering applications.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1776-cd

Year: 2025