Experimental study of a porous floating breakwater

Abstract

The paper presents a novel configuration of floating breakwater and its performance in waves. The structure is fabricated with large numbers of diamond-shaped blocks so arranged to reduce transmitted wave height and the mooring force. Two mooring modes, directional mooring and bidirectional mooring are considered in the tests. The influence of an impermeable vertical sidewall on transmission coefficient is estimated. The results examined under the present investigations are: K t, wave transmission coefficient ( K t= H t/ H i, H t—transmitted wave height, H i—incident wave height); K r, reflection coefficient ( K r= H r/ H i, H r—reflected wave height); E loss ( E loss = 1 − K r 2 − K t 2 ) , the value of the dissipation of incident wave energy; and mooring force per unit length of the breakwater ( F w denotes windward mooring force and F l denotes leeward mooring force for directional mooring, and F 1, F 2, F 3 and F 4 are four mooring forces for bidirectional mooring) of two mooring modes without sidewall. For the case of floating breakwater with impermeable sidewall, measured transmission coefficient K T ( K T= H T/ H, H T—the measured wave height in front of the sidewall, H—the wave height without structure and sidewall) is offered. The experimental results show that the proposed floating breakwater can reduce incident wave height by dissipating wave energy more than reflecting it.