近岸潮流泥沙输运的三维数值模拟

发布时间：2018-03-27 06:28

本文选题：ECOMSED模型　切入点：三维数学模型　出处：《太原理工大学》2014年硕士论文

【摘要】：河口海岸的泥沙输运问题是人类开发利用自然资源,从事各种生产活动必须要考虑的问题之一。河口泥沙的输运、沉降以及再悬浮等现象均具有三维性,采用潮流泥沙三维数学模型能够较为真实地模拟近岸河口潮流的运动特性以及悬浮泥沙与床沙之间的交换过程,因此,许多学者致力于这方面的研究,但由于泥沙运动相当复杂,其运动的机理、运动参数取值均具有不确定性。泥沙数值模拟还不太成熟,预报精度相对较差,结合工程实际进行的算例也较少。本文在ECOMSED模型的水动力模块和泥沙输运模块的基础上,将三维潮流泥沙数学模型应用到工程实际海域中,对罗源湾潮流泥沙输运进行了三维数值模拟,具体工作内容和结论如下： (1)通过查阅国内外的大量文献,对三维潮流及其泥沙输运数学模型的研究方法、研究现状等有了较全面的了解。 (2)分析罗源湾水文观测资料,掌握了源湾水域的自然状况,包括罗源湾的地形、气候特性、泥沙来源以及运移趋势、大小潮的水动力特性等。 (3)选取2003年的实测半月潮,进行了海域潮流特性的数值模拟,并将计算大、小潮K1～K3测点的表层、0.6H以及底层流速与实测情况进行了对比分析,吻合良好。 (4)结合罗源湾水动力以及泥沙输运特性,对泥沙参数进行敏感性分析,选取合理的运动参数。 (5)在潮流模拟的基础上,结合原体观测泥沙浓度,给出开边界的泥沙输运条件,并考虑粘性泥沙的絮凝以及再悬浮过程,对罗源湾三维悬浮泥沙进行数值模拟。 (6)计算模拟了1年的泥沙冲淤变化过程,为了便于与1999年～2003年的地形变化资料比较,对数值模拟1年的结果进行线性扩展获得4年淤积情况,给出了大、小潮K1-K3站点垂向平均浓度计算值以及淤积厚度等值线分布图,可以较好地反映罗源湾1999～2003年水底地形的变化。 (7)本文在罗源湾实际观测资料的基础上建立的潮流泥沙三维数学模型较为合理,能基本反映罗源湾泥沙输运的过程。 (8)研究成果对近岸水域的三维潮流泥沙数值模型研究具有一定的参考价值。
[Abstract]:Sediment transport in estuaries and coasts is one of the problems that must be considered in the exploitation and utilization of natural resources. Three-dimensional mathematical model of tidal current and sediment can be used to simulate the movement characteristics of tidal current and the exchange process between suspended sediment and bed sediment. However, because of the complexity of sediment movement, the mechanism of sediment movement and the value of motion parameters are uncertain. The sediment numerical simulation is still immature, the prediction accuracy is relatively poor, and the practical examples are few. Based on the hydrodynamic module and sediment transport module of ECOMSED model, this paper applies 3D tidal current and sediment mathematical model to the actual sea area of engineering, and carries out three-dimensional numerical simulation of tidal current and sediment transport in Luoyuan Bay. The specific elements and conclusions of the work are as follows:. 1) by consulting a large number of literatures at home and abroad, the research methods and present situation of 3D tidal current and sediment transport mathematical model are fully understood. 2) by analyzing the hydrological observation data of Luoyuan Bay, we have mastered the natural conditions of the waters of Luoyuan Bay, including the topography, climatic characteristics, sediment sources and transport trends of Luoyuan Bay, hydrodynamic characteristics of large and small tides, and so on. 3) the numerical simulation of tidal current characteristics in the sea area was carried out by selecting the measured half-moon tide in 2003. The surface layer (0.6H) and the bottom velocity of the K1~K3 measurement point of the large and low tide were compared with the measured results, and the results were in good agreement with the measured results. 4) according to the characteristics of hydrodynamics and sediment transport in Luoyuan Bay, the sensitivity of sediment parameters is analyzed and reasonable motion parameters are selected. 5) on the basis of tidal current simulation and combined with the observation of sediment concentration, the transport conditions of sediment at open boundary are given, and the three dimensional suspended sediment in Luoyuan Bay is numerically simulated considering the flocculation and resuspension process of viscous sediment. In order to compare with the topographic variation data from 1999 to 2003, a 4-year siltation is obtained by linear expansion of the results of the numerical simulation. The calculated values of mean vertical concentration and the contour distribution of deposition thickness at the K1-K3 station of the low tide can well reflect the variation of the bottom topography of Luoyuan Bay from 1999 to 2003. 7) based on the actual observation data of Luoyuan Bay, the three-dimensional mathematical model of tidal current and sediment is reasonable and can basically reflect the process of sediment transport in Luoyuan Bay. The research results have some reference value for the study of three dimensional tidal current and sediment numerical model in coastal waters.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV148

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