淤泥质海岸浮泥形成与运动的数学模型研究

发布时间：2018-06-29 10:43

本文选题：浮泥 + 水动力-粘性泥沙耦合模型　；参考：《天津大学》2014年博士论文

【摘要】：淤泥质河口海岸地区，浮泥是一种比较常见的具有特殊流变特性和高流动性的泥沙运动形态，浮泥的形成和运动对淤泥质海岸港口和航道淤积等实际问题具有重要影响。为此，本文针对浮泥的形成和运动过程，首先基于有限体积法建立了三维水动力-粘性泥沙耦合模型为描述浮泥的形成过程奠定基础，然后建立一维浮泥运动模型并在此基础上建立了三维水动力-平面二维浮泥双层模型描述浮泥的运动过程，最后结合大气模型、波浪模型以及模型耦合工具，建立了风-浪-流-粘性泥沙-浮泥集成模型。该集成模型进一步应用于研究不同风浪条件对典型淤泥质海岸连云港浮泥形成和运动以及航道淤积的影响。本文的具体研究内容和主要结论如下：（1）基于有限体积法建立了波、流共同作用下的三维水动力-粘性泥沙耦合模型，模型考虑了粘性泥沙悬扬运动过程的各种影响因素及水动力和粘性泥沙间的相互影响。选取相关实验数据对模型进行了验证，结果表明模型能够较合理地描述水动力和粘性泥沙运动，为合理模拟浮泥的形成奠定基础。（2）推导了非牛顿流体摩阻系数，并将摩阻系数表达式引入到基于浅水方程的一维浮泥运动有限差分模型中计算浮泥与底部床面间的摩阻力，模型的合理性获得实验验证。（3）结合三维水动力-粘性泥沙耦合模型和一维浮泥运动模型的研究成果，建立了基于有限体积法的非结构化网格三维水动力-平面二维浮泥双层模型，描述粘性泥沙落淤形成浮泥及浮泥的运动过程，同时考虑浮泥和水体间的相互影响。模型模拟上部水体和底部浮泥运动的能力获得相关实验验证。（4）河口海岸地区动力因素复杂，在台风等恶劣气候条件下可能在航道和港池中形成骤淤，结合水动力-浮泥双层模型、大气模型、波浪模型和模型耦合工具，，建立了三维风-浪-流-粘性泥沙-浮泥集成模型，并将模型应用于台风及大风期间连云港海域的水动力、泥沙、浮泥运动和航道淤积模拟。（5）以典型淤泥质海岸连云港为例，应用建立的集成模型研究不同风浪条件对连云港海域浮泥形成和航道淤积的影响。结果表明大风作用产生强浪，使底部泥沙大量悬浮并在动力条件较弱的航道中落淤，是产生浮泥和航道淤积的重要原因。
[Abstract]:In the muddy estuarine and coastal area, floating mud is a kind of sediment movement which has special rheological characteristics and high fluidity. The formation and movement of mud have an important effect on the silting of silt coastal ports and waterways. Therefore, in this paper, a three-dimensional hydrodynamic and viscous sediment coupling model is established based on the finite volume method to describe the formation process of the floating mud. Based on the model, a three-dimensional hydrodynamic-plane two-layer model is established to describe the motion process of the slime. Finally, combined with the atmospheric model, the wave model and the coupling tool of the model, a two-layer model is developed to describe the motion of the slime. An integrated wind-wave-flow-viscous sediment-mud model is established. The integrated model is further applied to study the influence of different wind and wave conditions on the formation and movement of floating mud in Lianyungang, a typical muddy coast, and the siltation of waterway. The main research contents and main conclusions are as follows: (1) based on the finite volume method, a three-dimensional hydrodynamic and viscous sediment coupling model under the interaction of wave and current is established. The model takes into account various factors affecting the suspended movement of viscous sediment and the interaction between hydrodynamic and viscous sediment. The relevant experimental data are selected to verify the model. The results show that the model can reasonably describe hydrodynamic and viscous sediment movements, and lay a foundation for reasonable simulation of the formation of floating mud. (2) the friction coefficient of non-Newtonian fluids is derived. The expression of friction coefficient is introduced to the finite difference model of one-dimensional slime motion based on shallow water equation to calculate the friction between the floating mud and the bottom bed. The rationality of the model is verified by experiments. (3) combined with the results of three-dimensional hydrodynamic and viscous sediment coupling model and one-dimensional sediment motion model, Based on finite volume method, a three-dimensional hydrodynamic-plane two-layer model of unstructured meshes is established to describe the motion process of slime and mud formed by viscous sediment deposition, and the interaction between sediment and water is taken into account. The ability of the model to simulate the movement of upper water and bottom mud has been verified by relevant experiments. (4) the dynamic factors in estuarine and coastal areas are complex, and sudden siltation may be formed in waterways and harbor ponds under severe weather conditions such as typhoons. A three dimensional integrated model of wind, wave, current, viscous sediment and mud is established by using the coupled tools of hydrodynamic double layer model, atmospheric model, wave model and model. The model is applied to the hydrodynamics of Lianyungang sea area during typhoon and strong wind. (5) taking the typical silt coast Lianyungang as an example, the integrated model was established to study the influence of different wind and wave conditions on the formation of sediment and channel deposition in Lianyungang sea area. The results show that the strong waves caused by the strong wind cause a large amount of sediment suspended at the bottom and silt fall in the channel with weak dynamic conditions, which is an important reason for the silt and channel siltation.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TV148

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