Numerical Investigation of an Ocean Brick System

A three-dimensional Computational Fluid Dynamics (CFD) model is developed to simulate an Ocean Brick System (OBS) placed in a wave tank. When stacked, ocean bricks are designed to withstand wave forces and ocean currents, enhancing the stability of offshore support structures, such as base supports of offshore wind turbines. In this study, the commercial software Ansys Fluent 2022 R1 is used for the simulations. A user-defined function (UDF) is developed to generate numerical waves that closely replicate those observed in experimental conditions. The numerical wave model is first validated against theoretical wave data, showing good agreement. The CFD model is then validated using experimental data from OBS tests conducted in the wave tank. Subsequently, the study investigates how OBS structures influence tidal waves—specifically, how they reduce the wave amplitude, and the pressure exerted on the bricks. Specifically, the wave amplitude reduction is more effective for waves with shorter wavelengths than for those with longer wavelengths, achieving up to a 70% reduction for waves with an amplitude of 0.785 m, a period of 5 s. Finally, a modification to the original brick geometry is proposed to further reduce wave amplitude and improve the stability of OBS platforms. For the same wave input, the modified brick geometry reduces wave energy effectively, achieving an 89.2% decrease in wave amplitude.