Performance Analysis Of A Semicircular Free Surface Breakwater

In recent years, with the development of the international economy and the demand for international trade, maritime transportation is the development assumes a trend to large-scale and the construction of harbors which services it step into the deep sea. But the traditional breakwater can not adapt to the deep water for the problems that construction cost is expensive, construction is difficult and water pollution can not be solved. Therefore, it is significant to esplore the reasonable cost breakwater which can be fit for the construction of deep water,soft foundation and has good function of dissipating waves and water circulation.In the present study, a new kind of perforated free surface semicircular naval structure is presented. And its wave dissipation characteristics have been systematically experimented and calculating analyze based on the physical model and numerical simulation. The main conclusions are as follows:(1)In the hydrodynamic analysis, the test model of the semicircular breakwater has been constructed with wall porosity varied at0(i.e., no perforations),9%,18%. The models were tested for three submergence depths with reference to the still water level in a wave flume under regular seas with different wave periods. The performance of the breakwaters was evaluated in the form of coefficients of transmission (ET), reflection (ER) and energy dissipation (EL).Based on the hydrodynamic analysis, come to the following conclusions:The SCB models made better barriers to wavetransmission when immersed with greater draft, and subjected to shorter period waves; The perforated SCB models had lower reflectivity and higher energy dissipation characteristics (in shorter wave periods) relative to the impermeable one. Therefore, the presence of the SCB9SCB18were inferred to be less obstructive to navigation in the vicinity.(2) In the physical model experiment, The hydrodynamic characteristics of the breakwater are investigated in regular and irregular wave conditions under the different water depths, submergence depths, wave heights and wave periods. The performance of the breakwater was evaluated in the form of transmission coefficient (ET), reflection coefficient (ER) and energy dissipation coefficient (EL), wave climate coefficient at the breakwater(EF、 EC).In summary, the breakwater performs better as an energy dissipater than as a wave reflector, and is suitable for offshore infrastructure construction.