||This research is mainly for reduction of the wave energy, how to cut down the wave energy to let it less impact on the coast or structures is important for coastal engineering goals. Make use of waves through the porosity structures of reflectivity, to understand the amount of wave energy attenuation.|
The test is carry on a cross-section sink, the sink has a wave maker in its end, and the other side is the porosity structure. Based on five different porosity structures type, in order to increase the active area between waves and structures and increase the porosity of the material, the water depth are 50cm、70cm and 90cm, and the waves period are from 1.2 sec to 2.7sec, the waves height range are use the waves steepness from 0.02 to 0.05 to make a selection, explore the reflectivity between the waves and the porosity structure relationship, and expectations to create a facility that can dissipate the waves energy and let the wave reflectivity less than 10%, sothe sink can do fixed bed test in the future.
The test are based on the waves steepness(H/L) and the dimensionless frequency rate(σ^2 h/g) to do a study with wave reflectivity, and discuss the waves break or not the relationship between the reflectance which are observed in the experimental process. The results show that the greater the wave period, the greater the reflectance, through the improvement of the structures, can effectively reduce wave energy, reducing its reflectance, as the long wave has higher reflectance, but in the wave absorption facility improve, the long wave can be more significant losses, and shorter wave which are not broken, its reflectivity greater than the long waves but the waves are broken informed that the waves broken is the main way to dissipate the waves energy.