CFD STUDY ON WAVE TRANSMISSION OF SUBMERGED HEMISPHERICAL SHAPED ARTIFICIAL REEF (HASR) BREAKWATER

Coastal erosion is the recession of shorelines and loss of land caused by waves, currents, and wind. Hemispherical Shaped Artificial Reefs (HSAR) can act as submerged breakwaters to mitigate erosion, offering structural protection while enhancing aquatic habitats and biodiversity. Designed to provide shelter for marine life, HSARs combine engineering with ecological benefits. Previous experimental studies on wave transmission over submerged breakwaters were conducted at the Hydraulic and River Engineering Laboratory of Bangladesh University of Engineering and Technology. This study demonstrates wave transmission across HSAR breakwaters using the Volume of Fluid (VOF) method with the Reynolds-Averaged Navier–Stokes (RANS) equations in the FLOW-3D numerical suite. The reefs were modeled using RHINOCEROS 5.0 software. The main objective is to determine wave transmission through numerical simulation. First, the model was validated against experimental results for submerged breakwaters. Further simulations assessed transmission with varying HSAR structural heights and designs. The findings showed close agreement between simulations and experiments, with percentage errors ranging from 4.1% to 16.7%. Results emphasize the significance of structural height in reducing the wave transmission coefficient, K_t. HSARs outperformed thalame breakwaters in transmission reduction, proving beneficial for coastal protection, environmental sustainability, and aquatic life.