【作者】 李孟国；

【导师】 文圣常； 蒋德才；

【作者基本信息】 青岛海洋大学 ， 物理海洋， 2002， 博士

【摘要】 本文研究了海岸河口水动力(潮流、波浪、波生近岸流)及其引起的泥沙运动的数值模拟问题。从科学性和应用的有效性、方便性和实用性考虑,在对海岸河口水动力与泥沙运动的数值模拟研究进行了全面系统的总结和回顾基础上,针对海岸河口海区的特点和已有数值模拟方法的缺陷和不足,通过理论上和数值技术上的研究改进,建立了多套水动力与泥沙运动的数学模型,这些模型都得到了实际应用的验证;另外,开发了关于不规则三角形网格的若干实用技术,综合介绍了有关泥沙模型中的若干参数的确定方法。实际应用结果表明,本文建立的多套数学模型能满足目前的海岸河口水动力与泥沙运动的数值模拟的需要,并且方便有效。本文的主要研究成果如下: 1.根据线性波动的叠加原理和波浪方向谱理论,推导出了非缓坡非均匀流场中考虑非线性弥散影响和底摩擦作用的多向不规则波传播的折射绕射方程;结合有限差分方法建立了综合考虑多种因素(非线性弥散影响、非缓坡地形、水流、波浪破碎、岛屿影响、底摩擦波能损失、折射、绕射)的多向不规则波(随机波)传播变形数学模型,该模型适合于海岸河口附近大面积复杂地形海区波浪场计算; 2.对波生近岸流基本方程理论和辐射应力理论进行了改进,加入了反映波浪破碎作用的项,使基本方程和辐射应力在破碎带内更为合理; 3.建立了基于矩形和三角形两种网格的二维潮流、考虑波浪作用的二维潮流、二维波生近岸流及二维泥沙运动的多套有限差分数学模型;考虑波浪作用的二维潮流数学模型和考虑水流作用的波浪数学模型联立求解即构成波浪潮流耦合的数学模型;更多还原

【Abstract】 This paper carries out studies on the numerical simulations of hydrodynamics(tidal current, water wave and wave-induced nearshore current) and the resulting sediment movement in coastal and estuarine waters. For scientificaalness and effectiveness, convenience and practicality in engineering applications, on the basis of comprehensive and systematic summing-up and review on the studies of hydrodynamics and sediment movement in coastal and estuarine waters, in accordance of features of coastal and estuarine waters and the drawbacks of the previous numerical methods and through study and improvement in theory and numerical technique, multi-sets of practical mathematical models of hydrodynamics and sediment movement are set up, which are all verified with practical applications. Moreover, a number of practical techniques on irregular triangular grid are developed, and determining methods of a number of parameters in the sediment models are comprehensively presented. Practical applications show that the multi-sets of mathematical models can satisfy the present need for numerical simulations of hydrodynamics and sediment movement in coastal and estuarine waters conveniently and effectively. The main research achievements are as follows: 1.Based on linear component wave theory and wave direction spectrum theory, a governing equation for multi-directional irregular wave transformation in non-uniform current and rapidly-varying topography with the consideration of bottom friction and nonlinear dispersion effect is derived, and then a multi-directional irregular wave transformation mathematical model taking into account multi-factors such as nonlinear dispersion effect, rapidly varying topography, current, wave breaking, island, bottom friction, refraction, diffraction is set up by means of finite difference scheme, which is suitable for wave field computation of large sea area with complicated bottom topography in coastal and estuarine waters. 2.The governing equations of wave-induced nearshore current and wave radiation stress are improved, in which terms reflecting wave breaking effect are added, thus making them more reasonable in the surfzone. 3.With both rectangular grids and triangular grids, multi-sets of finite-difference mathematical models of 2-D tidal current, 2-D tidal current with wave, 2-D wave-induced nearshore current and 2-D sediment are set up. The 2-D tidal current model with wave and the above wave model with current constitute a coupled tidal current and wave mathematical model. 4.By using σcoordinate transformation technique and finite difference numerical method, 3-D tidal current and 3-D sediment mathematical models with both rectangular grids and triangular grids are set up. Besides having advantages from σcoordinate transformation, the 3-D tidal current model has another advantage that it can take vertically–averaged current speed as its open boundaries, which is very convenient for the model operation and for the nesting operations between 2-D and 3-D models. 5.A number of practical techniques on irregular triangular grids are developed. 6.Determining methods of a number of parameters in the sediment models and their value ranges are comprehensively presented.更多还原