Experimental Study On Wave Dissipation Performance Of New Flexible Floating Breakwater

In the background of large exploitation of marine resources and large development of marine economic, it’s necessary to develop effective protective equipment to shield large offshore floating structures, such as floating docks. Compared with the traditional bottom-mounted breakwaters, the floating breakwaters attract more and more attention of engineers and researchers due to its advantages of simple structure, low cost, small impact on the ecological environment, rapid manufacturing and construction, etc. while the floating breakwaters aren’t applied in actual engineering because of poor performance of wave dissipation in the long-wave conditions.This paper presents a new flexible floating breakwater combining a variety of wave dissipation mechanism, looks like curtain-type, so call it Curtain-type Flexible Floating Breakwater(CFFB). Then studies the influence of relative width, wave steepness and floating plate on transmission coefficient, reflection coefficient and diffraction characteristics of the new flexible floating breakwater under regular waves through the 2D flume and 3D pool experiments.In 2D flume tests, this paper mainly discusses the influence of the various influencing factors on wave dissipation of CFFB. The relative width is the main factor affecting the transmission coefficient of flexible floating breakwater. The performance of wave dissipation achieves optimum when the relative width is about 0.3, and maintains steady with the increasing of the relative width.In 3D pool tests, the variation of transmission coefficient, reflection coefficient and diffraction coefficient with various influencing factors are all analyzed. It shows that the flexible floating breakwater can effectively solve the problem of poor wave dissipation performance in the long-wave condition under 3D waves. While the wave diffraction evolution of embankment becomes more favorable with the relative width increases.Comparing of the test results of 2D flume and 3D pool, the transmission coefficient of the flexible floating breakwater is better under 2D wave condition than under 3D wave condition. The D-value is between 0.10 and 0.25. Whatever kind of wave conditions, the wave dissipation properties of flexible floating breakwater present changing dramatically range and relatively stable range with steepness increasing. Floating board has a role in improving the wave dissipation performance, but it’s not obvious.