【作者】 梁志宏；

【导师】 金腊华；

【作者基本信息】 暨南大学 ， 环境科学， 2006， 硕士

【摘要】 本文根据珠江河口的水力特性，在总结现有研究成果的基础上，建立了平面二维潮流、泥沙、含盐度非耦合数学模型；通过拟合曲线坐标系下二维数学模型变换，将复杂计算域转变成规则计算域，使潮流、泥沙及含盐度方程的求解在规则计算域上进行；采用了分步全隐式有限差分法离散和求解水流运动方程，采用交错方向法离散和求解污染物输移扩散方程。由于引进了正交贴体坐标系，使边界网格线能够贴岸布置，既提高了模拟计算精度，又减小了采用矩形网格而引起的大量废网格物理量的储存和无效运算，增加了程序的通用性。对于模拟区域内随潮汐涨落而出没的浅滩，采用“富裕水深法”处理了因水位的波动而形成的动边界。对非恒定非均匀泥沙数学模型则采用分组粒径来模拟泥沙非均匀性，并根据挟沙能力与底质组成的关系，较好地解决了悬沙与底部泥沙的交换问题，从理论上保证了泥沙输移模拟的精度。在本文结尾部分，还将所建立的模型应用于洲头嘴附近河道的水流、泥沙和含盐度计算。研究结果表明，该模型能较好的模拟复演河道水流、泥沙、含盐度输移过程，且计算稳定性好，速度快、精度高，具有良好的实用性，并为进一步深入研究打下了基础。更多还原

【Abstract】 Considering the kinematical characteristics of Pearl River Delta and based on the previous studies by other researchers, a non-coupled 2-D mathematic model for flow、 sediment and salinity is presented with staggered body-fitted grids in the orthogonal curvilinear coordinate for complex boundary rivers. The Double-Sweep-implicit finite difference scheme is adopted to solve the momentum and continuity equations of flow motion and the substance transport equation is solved by Alternative-Direction-Implicit method. The present schemes have many advantages such as yielding more accurate numerical results, having high resolution, being well suitable and so on. "The water depth margin technique" is applied to solve the problem of moving boundary caused by varied water level. The model adopts the technique of grouping granule for unsteady and non-homogeneous sediment model and a formula for the interchange between suspend sediment and bed materials is developed in view of the relations of flow carrying capacity and bed-load sediment, it simulates well the physical process in theory. And the research with the measured data of typical hydrology is made, the studies show that the model adjustment and verification were performed in conjunction with field data. The simulated results coincide well with measured data. And the basement for the farther research is founded.更多还原