波浪与开孔沉箱相互作用的数值研究

发布时间：2018-11-27 18:45

【摘要】：开孔沉箱作为一种新型港口和海岸防护结构物自上世纪中叶被提出以来,因其具有消浪效果好且工程成本低等优点,已得到广泛的科学研究和工程应用。就目前的研究成果来看,对于波浪与开孔沉箱相互作用的物模试验成果较为丰富,但是数值模拟研究特别是波浪与双层开孔沉箱相互作用的数值模拟成果相对较少且数值方法较为单一,其中时域内准确地完成对自由水面的追踪,是建立波浪与开孔沉箱相互作用数值模式过程中的难点问题之一。CLEAR-VOF方法的问世对于解决该问题提供了新的思路,这是本文进行数值计算依赖的关键手段。本文首先利用三步有限元方法离散Navier-Stokes方程,并借助CLEAR-VOF方法、大涡模拟方法追踪水体自由表面和模拟湍流效应,建立了二维数值波浪水槽,成功模拟了规则波的传播。籍此研究了规则波作用下单层开孔沉箱的反射率和波浪总水平力,并与其他学者的物模试验结果和数模结果进行了对比,吻合良好且规律性明显,为波浪与开孔沉箱相互作用问题的研究探索了一种新的数值模式。在此基础上,本文进行了波浪与双层开孔沉箱相互作用的数值试验,分析了反射率和波峰总水平力比等指标,并与其他学者的物模试验结果进行对比,吻合良好,进一步验证了本文数值模式的可靠性。分析了总消浪室相对宽度、后消浪室相对宽度、波陡、相对水深和前开孔墙开孔率等无量纲量对波谷总水平力比的影响关系并成功拟合经验关系式,指出双层开孔沉箱波谷总水平力比主要受总消浪室相对宽度和相对水深的影响且大致呈现线性递减关系。最后以某工程为例,进行了实际尺度单层和双层开孔沉箱结构物的验证分析,表明本文所建数值模式在开孔沉箱工程设计和研究领域的适用性。
[Abstract]:As a new type of port and coastal protection structure, caisson has been widely studied and applied in engineering because of its good wave attenuation effect and low engineering cost since it was put forward in the middle of last century. According to the current research results, the results of the physical model tests on the interaction between waves and open-hole caisson are relatively rich. But the numerical simulation, especially the numerical simulation of the interaction between waves and double-layer caisson, is relatively few and the numerical method is relatively simple, in which the tracking of free water surface is completed accurately in time domain. It is one of the difficult problems in the process of establishing a numerical model of wave-open caisson interaction. The advent of CLEAR-VOF method provides a new way to solve this problem, which is the key means of numerical calculation in this paper. In this paper, the three-step finite element method is first used to discretize the Navier-Stokes equation. With the help of CLEAR-VOF method, the large eddy simulation method is used to track the free surface of the water body and to simulate the turbulent effect. The two-dimensional numerical wave flume is established and the regular wave propagation is successfully simulated. In this paper, the reflectivity and the total wave horizontal force of a single-layer open-hole caisson under the action of regular waves are studied, and the results are compared with those obtained by other scholars, and the results are in good agreement with those of the numerical models. A new numerical model is proposed for the study of the interaction between waves and open caisson. On this basis, the numerical experiments on the interaction between waves and double-layer caisson are carried out, and the reflectivity and the ratio of wave peak to total horizontal force are analyzed. The results are in good agreement with those obtained by other scholars. The reliability of the numerical model is further verified. The effects of dimensionless measures such as the relative width of the total wave suppression chamber, the relative width of the rear wave suppression chamber, the steep wave, the relative water depth and the opening ratio of the front hole wall on the total horizontal force ratio of the trough are analyzed and the empirical relations are fitted successfully. It is pointed out that the total horizontal force ratio of the double deck caisson is mainly affected by the relative width and the relative water depth of the total wave dissipating chamber and shows a linear decreasing relation. Finally, taking a project as an example, the verification and analysis of single-layer and double-layer open-hole caisson structures are carried out on a practical scale, which shows the applicability of the numerical model established in this paper in the field of engineering design and research of open-hole caissons.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U656.3;U652.3

【参考文献】