波流共同作用下的二维泥沙数学模型研究

发布时间：2018-02-09 08:39

本文关键词： 波流共同作用泥沙数学模型动边界技术泥沙源项　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：在河口海岸地区,由于波浪和潮流的综合作用,泥沙的运动规律变得更加复杂,波流作用下的泥沙运动仍是当前泥沙数学模型理论的重点研究内容。首先对波流共同作用下的泥沙数学模型、潮流数值模拟中潮间带的动边界问题和水动力学数学模型并行计算技术的相关研究工作进行回顾,而后以基于有限体积法建立的COASTALTOOLs数学模型为基础,在其二维潮流模块(2DTC)中考虑波浪的作用,加入泥沙运动模块(2DST),建立了泥沙运动数学模型,具体研究工作如下:(1)以原有的COASTALTOOLs模型为基础,将程序中现存的错误和不合理之处(例如泥沙源项计算公式、波流统一角度取值标准、数值计算中逻辑关系等)进行修正,使模型更加完善;(2)在程序中增加泥沙开边界条件,地形更新,波浪场与SWAN耦合的接口,以及OpenMP并行计算等,从而可以更加快速合理地求解波流共同作用下的二维潮流数学模型和泥沙数学模型;(3)在理论方面,改进带有淹没度的连续性方程离散求解过程,并提出一种新的计算动边界的方法,即在整个计算域中求解时不区分干湿单元,控制方程统一求解,使得在干湿交界处干网格和湿网格的物理量计算更加准确;(4)通过对典型算例的数值模拟,考察了在不同的水流波浪条件下泥沙运动的情况,分析不同泥沙源项计算方法对流速、波高以及波向的敏感性;通过对均匀底坡算例的数值模拟,考察了改进的动边界方法的可行性,以及不同水深条件下潮流、波浪和泥沙相关物理量的分布趋势。
[Abstract]:In estuarine and coastal areas, the movement of sediment becomes more complicated by the combined action of waves and tidal currents. The sediment movement under the action of wave and current is still an important part of the theory of sediment mathematical model. Firstly, the mathematical model of sediment under the action of wave and current is studied. In the numerical simulation of tidal current, the dynamic boundary problem of intertidal zone and the parallel computing technology of hydrodynamic mathematical model are reviewed, and then the COASTALTOOLs mathematical model based on finite volume method is used as the foundation. Considering the action of wave in its two-dimensional tidal current module, the mathematical model of sediment movement is established by adding sediment movement module 2DST. The specific research work is as follows: 1) based on the original COASTALTOOLs model. The existing errors and unreasonableness in the program (such as the calculation formula of sediment source term, the standard of unified angle of wave and current, the logical relation in numerical calculation, etc.) are corrected, so that the model is more perfect and the boundary conditions of sediment opening are added in the program. Topographic update, interface between wave field and SWAN, and parallel computation of OpenMP can be used to solve 2-D tidal current mathematical model and sediment mathematical model under the interaction of wave and current more quickly and reasonably. The discrete solution process of continuous equation with submergence is improved, and a new method to calculate the moving boundary is proposed, that is, the dry and wet elements are not distinguished in the whole calculation domain, and the governing equation is solved uniformly. It makes the calculation of physical quantity of dry grid and wet grid more accurate at the junction of dry and wet. Through the numerical simulation of typical examples, the sediment movement under different current and wave conditions is investigated, and the calculation methods of different sediment source terms are analyzed for the velocity of flow. The feasibility of the improved dynamic boundary method and the distribution trend of tidal current, wave and sediment related physical quantities under different water depth are investigated by numerical simulation of a numerical example of a homogeneous bottom slope.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV148

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