一种简洁有效的河道平面二维流动数值模型

本文提出了一种简洁有效的河道平面二维流动数值模型。模型采用跟踪河道中心线走向的正交曲线坐标系，曲线网格可用代数方法直接生成。这种河道正交曲线网格较好地适合了河流的形态特征及流动特性，模型基于显式有限差分，利用水面回算消除不稳定性。并使模型在空间和时间上均达到二阶精度。模型采用显式非恒定流渐近迭代法计算河流恒定流场，为了有效地抑制非线性不稳定性发展，二维模型初值由准二维计算结果提供。本文针对弯道水槽试验成果。多体绕流，边池回流和天然山区河流情况，对数值模型进行了测试和验证。结果表明，模型具有较强的模拟复杂流态的能力。

A simple and efficient 2D depth-averaged numerical model for channel flow field

A simple and efficient 2D depth averaged numerical model was proposed for channel flow field. An orthogonal curvilinear coordinate system following the alignment of the river was employed, which can be generated by the algebraic method. The grid could be attached to the channel geometry, and adapted to the flow features of channel. The second order explicit finite difference scheme was applied. The unsteady character of the model was used with an iterative technique to approach channel steady flow. The initial condition of the model was obtained by quasi two dimensional method so as to control the nonlinear instability. The model was tested with experimental bend flow data, flow around multi body, circulation in the side pool, and natural mountainous channel. It is demonstrated that the proposed model has the capabilities to simulate complex flow patterns.