1. For the single fixed FB the efficiency of the structure can be considered satisfactory for B/L greater than 0.25 and dr/d
ranging between 1/5 to 1/3.
2. The single fixed FB operates in a highly reflective manner with values of the reflection coefficient ranging between 0.4
(longest wave period) and 0.9 (shortest wave period).
3. Energy dissipation is due to strong oscillating, air–water vortices occurring in the front (upstream) part of the structure.
Higher energy dissipation is observed in the case of irregular waves.
4. The heave motion FB operates in a dissipative manner, with much lower reflection than that of the single fixed FB. The
Cd coefficient ranges between 0.45 and 0.9 for long and short period waves, respectively.
5. The attached plate at the front part of the FB considerably enhances the efficiency of the structure.
6. No significant differences are observed between the impermeable and the permeable (with porosity 0.62 and small
thickness) plate cases.
7. The most efficient configuration is found to be the double FB, with transmission coefficient values as low as 0.12 and B/L
equal to 0.3.
8. In terms of cost-effectiveness, the configuration of the FB with the attached front plate should be considered the most efficient for design.