考虑泥沙分选及床沙级配调整的二维数值模拟研究

在正交曲线坐标系下建立平面2维河流数学模型,包括水流模型、泥沙模型。在前人研究成果的基础上,通过修正泥沙模型中非均匀沙挟沙力公式以考虑泥沙分选影响;并根据近底床沙质量守恒方程计算床沙级配调整。利用seal水槽下游细化试验资料,对模型进行了验证,结果表明,本模型能够合理模拟水槽地形及其床面泥沙分布变化,反映试验水槽沿程细化的趋势,具有研究实际河道河床变形及床沙分布变化的潜力。

2D mathematical modeling for grain sorting processes and grain size distributions

A depth-averaged finite difference two-dimensional hydrodynamic-morphological and sediment transport model is presented in the orthogonal curvilinear grid system. Based on the previous work, the influence of selective sorting is taken into account in the sediment model by modifying the sediment transport capacity; the grain size distribution is simulated according to the sediment mass conversation equation for bed surface. The model is applied to the experiment on downstream fining by seal. The simulated bed profile and grain size distributions are in acceptable agreement with the field measurements. It illustrates the capability of the two dimensional models in predicting the river morphology and grain sorting processes for actual rivers.