【作者】 王俊；

【导师】 李华军；

【作者基本信息】 中国海洋大学 ， 水利工程（专业学位）， 2014， 硕士

【摘要】 潜堤是最常见的近岸防护物，用于减弱外海波浪，保护海滩和岸上设施及建筑物。由于近岸波浪复杂多变，增加了对近岸波浪数值模拟的难度，使得波浪与潜堤相互作用的数值模拟精度不高，无法达到工程应用程度，因此，精确地模拟波浪与潜堤相互作用一直是海岸工程领域内的研究热点。本文研究利用物理模型试验与数值模拟相结合的方法进行了研究，来验证所建立的数值水槽能否精确模拟波浪与潜堤相互作用。物理模型试验在中国海洋大学海工实验室的水槽中进行波浪与潜堤相互作用的断面试验，物理模型对象是梯形潜堤，波浪类型为规则波和不规则波两种。利用波高仪采集波高数据，流速仪率定加流时流速。数值模拟采用计算流体动力学（CFD）软件Flow-3D，基于求解连续性方程和不可压缩粘性流体运动的Navier-Stokes方程，结合RNGκ-ε湍流模型，采用VOF法进行自由表面追踪，建立二维数值波浪水槽。在已有的Outflow出流边界的基础上，结合多孔介质以及变步长法进行末端消波。通过物理模型试验结果对比验证，优化调整多孔介质孔隙直径和变步长网格步长，获得优化消波效果的二维数值波浪水槽。在数值波浪水槽中添加潜堤模型，模拟波浪在潜堤上的传播过程，数值模拟与物理模型试验结果吻合良好。特别指出，非线性作用较强的堤顶部分的模拟结果与实验结果基本一致，说明本次研究所建立的Flow-3D数值波浪水槽能够较好的模拟波浪与潜堤的相互作用。通过本次研究，在结合多孔介质和等差变步长网格法进行消波时，孔隙直径0.3m，等差值0.05m的组合在所有研究组合中消波效果最好。进一步数值模拟研究表明，潜堤坡度对潜堤透射系数影响很小；当加流流速从-0.1m/s变化到0.3m/s时，潜堤透射系数先增大后减小，在流速为零时达到最大；潜堤透射系数随堤顶相对高程的增加而增大，随波浪周期的增加而减小。更多还原

【Abstract】 Submerged breakwater is one of the most common nearshore breakwaters, whichis widely used to prevent and weaken offshore waves, protect the coast from erosioncaused by the wave and protect the beach and other structures and facilities that arenear the sea. Wave will become deformed because of the complicated topography ofoffshore, resulting in complicated and changeable of the nearshore wave, which makethe wave simulation more difficult, that induce the numerical simulation ofinteractions between waves and submerged breakwater can’t meet the engineeringstandards. So the accurately numerical simulation, interactions between waves andsubmerged breakwater, has become a research hot topic in the field of coastalengineering. This paper will study by the experiment and numerical simulation inorder to check whether the numerical tank could accurately simulate the interactionsbetween waves and submerged breakwater.The experiment is held in the wave tank of marine engineering lab of Oceanuniversity of China; the physical model is trapezoidal submerged breakwater, thewave include regular wave and random wave, the model of submerged breakwaterinclude slope1:2and slope1:5. The wave gauge record wave high, the ADV checkthe current velocity.In this paper, computational fluid dynamics (CFD) software Flow-3D, based onsolving the continuity equation and the incompressible Navier-Stokes equations ofviscous fluid motion, combined RNGκ-ε turbulence model for free surface trackingusing the VOF method, a two-dimensional numerical wave flume is established, in theuse of existing Outflow boundaries on the basis of flow, combined with a porousmedium and variable step method to the end of the tank.By contrast with the physical model test results analysis, porosity and pore structure optimization variable step size grid step long, and then verify the feasibilityand effectiveness of numerical simulation. Submerged breakwater model has beenrefined and validated in the tank to simulate the propagation of waves over submergedbreakwaters, and comparative analysis of physical experiments and numericalsimulation model, simulation optimization at the same time, to get a better fit with theexperimental results numerical solution to analyze waveforms before and after theevolution of submerged breakwater, indicating that Flow-3D numerical model can bea good wave simulation, numerical simulation study for future waves and submergedbreakwater interactions provide valuable experience.The study found in the use of porous media and arithmetic variable step sizeclipping grid method, pore diameter taking0.3m, when the arithmetic take0.05m,clipping effect is relatively best, further studies have shown that the slope of thesubmerged breakwaters have less effect on the transmission coefficient；when thevelocity changes from-0.1m/s to0.3m/s, the transmission first increased and thendecreased, the maximum point corresponding to the velocity of zero; the transmissioncoefficient increases as relative depth of submergence increase, on the contrary, thetransmission coefficient decreases as the period increase.更多还原