Experimental Study on the Hydrodynamic Characteristics of a Fixed Comb-Type Floating Breakwater

Abstract

A comb-type floating breakwater is a new wave dissipation structure with particular force and dissipation performance advantages due to the two wave-reflecting surfaces. In this article, physical model experiments are used to study the hydrodynamic characteristics of a fixed floating comb breakwater and two structural optimization-based measures under the combined action of regular waves, irregular waves, and wave currents. The effects of factors such as the relative width, relative wave height, water flow velocity, and irregular waves on the transmission coefficient of the breakwater are analyzed. In addition, the characteristics of the transmission wave waveform are analyzed based on the time and frequency domains. The results show that (1) the wave transmission coefficient of a comb-type floating breakwater is lower than that of a rectangular floating box for long-period waves, while the transmission coefficient is larger than that of a rectangular floating box for short-period waves. (2) Under combined current and waves, the superimposition of bidirectional currents can increase the transmission coefficient, and the transmission coefficient increases with increasing current speed. The superimposition of the anti-directional current can decrease the transmission coefficient. (3) Moreover, with the same wave parameters, the transmission coefficient for irregular waves is larger than that of regular waves. (4) Finally, extending the bottom plate and adding lower baffles can effectively enhance the wave dissipation effect of the comb-type floating breakwater while also stabilizing the transmitted wave waveform.