Experimental Study Of Wave-dissipating Performance Of Perforated-pipe Breakwater

In recent years, many domestic and foreign researchers have investigated the wave-dissipating performance of penetrating breakwater. The characteristic of penetrating breakwater is that the upper wave attenuation structure supported by piling and the lower part can be permeable. Its advantage is that the exchange of the bottom waters would be free and the port deposit would be reduced.That structure will prevent the happening of the phenomenon of "dead" and cost few money; Its defect that the engineering application fields have certain restriction and the wave elimination effect is not very ideal in long cycle waves conditions. Because of the complexity of this problem, the previous domestic and foreign researchers’studies focus on the experimental investigation of the penetrating breakwater.The thesis propose a kind of penetrating breakwater composing of a lot of pipes which diameter increase gradually from up to down. The pipe section is circular where the water points within would be vibrated when the wave through the pipe. At the same time, the water will be interacted with internal air of the pipe to consume the wave energy to achieve the purpose of wave elimination. The wave-dissipating performance of perforated-pipe breakwater and the relationships of wave transmitssivity and reflectivity among the structure parameters and the wave’s elements are mainly studied in three aspects.In theory aspect, the paper summarizes the studies of the formula derived by domestic and foreign scholars for the wave transmissivity and reflectivity of the perorated breakwater. It mainly analyzes the process of the derivation of formula which inferred by domestic scholars of the reflection coefficient of the perforated-pipe breakwater.The relationships of wave transmissivity and reflectivity among the constructed width, the slope, the pipe diameter and the wave steepness are carefully studied by physical simulation. A comparison of wave attenuation effectiveness also be validated between a good kind of structure on a level board structure. The results indicate that the perforated-pipe breakwater have good performance on wave-dissipating.The thesis also uses the commercial fluid analysis software of Fluent to build simple two dimensional perforated-pipe breakwater models and tentatively simulate the wave-dissipating effect of the breakwater. A comparison of the physical result and the numerical simulation indicate that the variation regular of the two analysis results is agreed on the wave transmissivity and reflectivity of the perorated breakwater, but the numerical results same a little large.Through the theoretical summary, the physical model tests and numerical simulation on wave-dissipating performance of perforated-pipe breakwater, the result indicates that the wave-dissipating performance of the breakwater is good. Because of the simply structure and lower cost, the perforated-pipe breakwater has certain practical in previous projects.