Mooring System Investigation Of Floating Breakwater In The Waters With Large Tidal Ranges

The applications of floating breakwaters are more and more extensive because of their easy construction, low cost and so on. However, applications of floating breakwaters are limited in Fujian costal area and Taiwan Strait of our country due to the large tidal ranges. On the one hand, laid length of mooring lines will be long for the low tide which will result in the motion of floating breakwater large. On the other hand, mooring force will be very large for high tide which will threaten to safety of floating breakwater. Therefore, the influences of different mooring types on the motion responses, mooring forces and transmission coefficients of floating breakwater were investigated. After analysis, suggestions were given for mooring types that were suitable for large tidal ranges.Firstly, the paper provides kinds of mooring configurations and mooring lines combinations of mooring system that will be investigated. Mooring configurations contained//type,×type,人type and八type. The八type would be performed under3D experimental condition. The//type would be investigated both in2D and3D experimental conditions. Mooring lines combinations contained chain+clump, chain+heave chain, chain+wire rope, chain+nylon rope, all of those were studied under2D experimental condition.Secondly, experimental method was used to study the influences of different mooring configurations i.e.//type, X type,人type on the motion responses, mooring forces and transmission coefficients of floating breakwater models in2D condition for large tidal ranges. A kind of mooring configuration that was suitable for lager tidal ranges was given after discussing the performance of every mooring configuration under different relative width and different incident wave height. The advantages and disadvantages of different mooring lines combinations in condition of large tidal ranges were investigated in the same way.Thirdly, motion responses, mooring force and transmission coefficients of floating breakwater with//type and八type were investigated in3D experimental condition for large tidal ranges. After analysis we know that motion, mooring force and transmission coefficients of floating breakwater in3D experimental were larger than2D. We can also see the八type was superior to//type. Lastly, numerical calculation was perfomied on free floating and moored floating by using of hydrodynamic software AQWA. The result showed that the effect is good to calculate floating breakwaters by AQWA.