长江口二维非均匀悬沙数值模拟

2-D Mathematical Model for Nonuniform Sediment Transport in Yangtze Estuary

针对长江口水流泥沙运动的特点建立了非均匀悬沙的平面二维数值模型。在模型中考虑了波浪对流场的影响和对水流挟沙力的影响 ,在确定悬沙絮凝沉速时考虑了泥沙粒径、盐度、含沙量及水流紊动的影响。悬沙模型建立在曲线坐标下 ,悬沙输运方程采用破开算子的方法求解 ,平流项采用UltimateQuickest格式求解 ,提高了计算的精度。通过实测资料对数学模型计算的悬沙含量进行检验 。

A 2 D horizontal mathematical model is established for suspended sediment transport based on the character of hydraulic and suspended sediment in Yangtze estuary. In the model the effects of wave on momentum equation and sediment capacity are considered. The fine sediment settling velocity due to flocculation is determined by sediment grain, salt, sediment concentration, and flow turbulence. A boundary fitted curvilinear coordinate system has been deployed to obtain a more accurate solution of SSC. The operator splitting algorithm and the Ultimate Quickest scheme have been used to solve the sediment transport equation. The calculated results are in close agreement with field observation, which shows this model can predict suspended sediment transport in Yangtze estuary.