The experimental results for fixed FB with attached front plate for both regular and irregular waves are presented in Figs 13–15. In Fig. 13, experimental results of Ct , Cr and Cd for the FB with the attached impermeable plate are compared with the ones for the corresponding single fixed FB with the same overall draught (dr/d = 1/4). The FB with the attached front plate performs as efficiently as the single fixed FB with the same overall draught. Similar conclusions can be derived for irregular waves (Fig. 15, left column). This configuration, the FB with the attached front plate, achieves more efficient hydrodynamic performance than that examined by Tolba (1998) and Christian (2000) with an attached plate in the middle part of the structure keel. This is due to the fact that generation of energy and turbulent eddies occur in the front part of the structure, and hence a mechanism, like an attached plate for dissipating energy in this region, is more effective than a similar mechanism in another part of the structure (middle or end region). Furthermore, the proposed configuration
provides more dissipation since reflection is lower and dissipation higher. This is mainly due to the increased local turbulence developed behind the plate as confirmed by video analysis performed by the authors.