Effect of submerged depth on the flow field around different artificial reefs

This study explores the hydrodynamic responses of artificial reefs at varying submergence depths (Z/D), with particular emphasis on free surface effects. Numerical simulations show that wave–structure interactions significantly affect flow dynamics, especially in shallow-submerged conditions, leading to increased horizontal forces, upwelling velocities, and vorticity. As submergence depth increases, wave influence weakens and the surrounding flow field stabilizes. When reefs are placed on the seabed, strong bottom boundary effects induce a sharp rise in vertical force and alter internal flow patterns, highlighting the role of seabed interaction in hydrodynamic loading. Comparative analysis between single-opening and four-opening reef models indicates that while overall performance is similar, the four-opening design enhances free surface interaction, upwelling, and wake stability. These results emphasize the need to optimize both submergence depth and structural porosity to improve the ecological performance and hydrodynamic stability of artificial reefs, particularly in wave-dominated shallow coastal environments.