Experimental Investigation of An Inclined, Floating Breakwater – A Case Study With Porous Design And Bio Enhancing Features

Over the past two decades, interest in the study of floating breakwaters has increased owing to the advantage of lower investment and being environment friendly. The use of a simple, inexpensive, and effective type of floating breakwater is increasingly becoming a necessity in shoreline and marine structure protection. This study concerns the hydrodynamic behaviour of a new type of free surface inclined porous floating breakwater in the purpose of wave attenuating, allow the sediment to pass through and to increase the aeration near onshore. The surface will be rough, porous and partially permeable with the purpose of disturbing the flow over the volume as well as creating an aerated turbulence in, and around, the structure and inclination of the structure is to induce the wave breaking. The inclined structure supported by two ballast floating box which uses several configurations of rocks and artificial concrete units for wave attenuation mechanisms. A series of experiments were carried out on the new floating breakwater model with six different types of porous configuration with different porosity and surface roughness to compare their performances. The hydrodynamic effectiveness which is presented as a function of the wave transmission coefficient, reflection coefficient is investigated experimentally. The action of 2D regular and irregular waves with wide ranges of wave heights and periods were considered. The motion responses of the floating breakwater with directional mooring line have also been measured. Emphasis is given on the effect of the incident wave characteristics; the inclined angle of the floating breakwater was kept at 15 degrees for all the set of experiments. A two-dimensional wave flume was used in the experiment; the incident and transmitted waves, the tensions on the mooring lines and the motion responses of the floating breakwaters were measured. Results showed that the new floating breakwater had a better performance for mid-level porosity and roughness in long and short-wave cases. The free body movement was significantly reduced, especially for short waves. However, the potential to implement bio enhancing features will be discussed and tested to investigate whether the breakwater can act as an artificial floating reef.