Wave attenuation by multiple slotted barriers with a zig-zag arrangement -A physical and numerical approach

In the present study, scattering of surface gravity waves by multiple slotted vertical barriers arranged in a zig-zag manner is analyzed by employing Computational Fluid Dynamics (CFD) and validated with physical model tests. The porosity of the vertical slotted barrier is varied from 10% to 40%, and the number of slotted barriers varied from 1 to 6. The results from CFD correlate well with the laboratory measurements on the scattering coefficients for a wide range of input conditions giving a high level of confidence. For relatively short waves (h/λ > 0.3, h- water depth and λ- wave length), slotted barriers up to 3 numbers and porosity from 20% to 30% are required to achieve wave transmission coefficient in the range of 0.2 to 0.3. For relatively long waves (h/λ < 0.3), slotted barriers of 5 to 6 numbers and porosity in the range of 10% to 20% are needed to obtain wave transmission of 0.2 to 0.3. The results presented in this study can be used for a wide range of wave damping applications in the field of coastal engineering.