防波堤对近岸波生流及其作用下泥沙输运影响的数值模拟研究

发布时间：2018-05-23 11:51

本文选题：缓坡方程 + 水动力　；参考：《大连理工大学》2014年硕士论文

【摘要】：近岸波浪及波浪破碎后产生的近岸流是近岸泥沙输运的重要水动力因素。其中波浪在近岸区域的掀沙作用比较明显,波浪破碎所产生的近岸流起着关键的输沙作用。防波堤对海岸工程和海床冲淤的防护具有非常重要的作用。因此,研究防波堤对近岸波浪、近岸流及其作用下泥沙输运的影响,对于准确研究海岸线的侵蚀与淤积,进一步解决相应的实际工程问题具有非常重要的意义。本文基于近岸波浪模型、近岸流模型及泥沙输运模型对近岸波浪、近岸流及防波堤对近岸流和泥沙输运过程的影响进行了数值模拟研究。研究中,首先基于全面考虑近岸波浪折射、绕射效应的抛物型缓坡方程、考虑波浪影响效应的平面二维浅水方程,建立了近岸波浪及波生流数值模型。应用所建模型对土耳其地中海的Obakoy海岸波浪、波生近岸流进行了数值模拟,验证分析了模型在实际近岸海域的有效性和适用性,并对该海岸波浪沿不同方向入射时破碎所形成的近岸波流场进行了讨论分析。在近岸波浪及近岸流数值模型研究的基础上,结合平面二维悬沙和底沙输运方程及海岸演变模型,建立了近岸波流场中的泥沙输运及海岸演变数值模型。采用著名的LSTF波浪和近岸流作用下的泥沙输运物理模型试验结果对所建数值模型进行了分析验证。在此基础上,应用所建数值模型模拟并分析了不同波浪入射条件和防波堤布置方式对近岸波生流及其作用下泥沙输运的影响。研究结果表明,本文所建数值模型可以有效地用于模拟近岸波浪和近岸流及其影响下的泥沙输运和海岸演变过程；合理的防波堤布置方式可以有效地防护近岸波浪和近岸流对岸滩的侵蚀。
[Abstract]:Inshore waves and the inshore currents produced by wave breakage are important hydrodynamic factors for sediment transport. The sediment lifting effect of wave is obvious in the coastal area, and the nearshore current caused by wave breaking plays a key role in sediment transport. Breakwater plays an important role in coastal engineering and the protection of seabed erosion and deposition. Therefore, it is of great significance to study the influence of breakwater on coastal waves, inshore currents and sediment transport under the action of shoreline erosion and siltation, and to further solve the corresponding practical engineering problems. Based on the inshore wave model, inshore current model and sediment transport model, the effects of inshore wave, nearshore current and breakwater on the inshore flow and sediment transport process are numerically simulated in this paper. The numerical model of near-shore wave and wave-induced current is established based on the parabolic gentle slope equation considering the wave refraction and diffraction effect and the plane two-dimensional shallow water equation considering the wave effect. The model is applied to the numerical simulation of the Obakoy coastal waves and waves in the Turkish Mediterranean Sea, and the validity and applicability of the model in the actual coastal waters are verified and analyzed. The near-shore wave flow field caused by the breakup of the coastal wave along different directions is discussed and analyzed. Based on the study of numerical models of near-shore waves and near-shore currents, combined with two-dimensional suspended sediment transport equations and coastal evolution model, a numerical model of sediment transport and coastal evolution in near-shore wave and current field is established. The results of the physical model test of sediment transport under the action of famous LSTF waves and near-shore currents are used to analyze and verify the established numerical model. On this basis, the effects of different wave incidence conditions and breakwater arrangement on the near-shore wave-induced current and sediment transport under the action of the wave are simulated and analyzed by using the established numerical model. The results show that the numerical model presented in this paper can be used to simulate the sediment transport and coastal evolution under the influence of inshore waves and inshore currents. The reasonable arrangement of breakwater can effectively prevent the erosion of shoreline caused by inshore waves and inshore currents.
【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】：U656.2;TV149

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