2D-V Hydrodynamics of Double Floating Breakwaters

Interactions of regular waves with a double, fixed, pontoon type, floating breakwater (FB) are studied numerically with the use of a 2DV Unsteady Reynolds Averaged Navier-Stokes (URANS) model. The study is focused on the effect of the structure width and spacing, both made dimensionless with the wave length (W/L and S/L), on the reflection, transmission and dissipation characteristics. The results of the numerical model are in good agreement with available large scale experimental data. Ct decreases with increasing W/L for all S/L; for a 100% increase of W/L a 62% (maximum) and a 34 % (minimum) decrease of Ct is found for S/L=0.25 and S/L=1.04 respectively. The effect of relative spacing S/L is not monotonic since Ct exhibits several maxima and minima with S/L. Better results are obtained for S/L<0.75 with Ct values less than 0.1.