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用有限单元法导出了描述宽阔密植被泛滥区内桥渡稳定二维缓流的数学模型。借助数值方法联立求解该水流方程组,得出对于所规定的边界条件在流区范围内的水面高程与流速的空间分布。将Galerkin的加权余数法应用于基本微分方程组以构成有限单元表示法。为模型选择的单元形状为三角形,用二次型函数定义单元流量,用线性型函数定义水深。对于正交的、斜交的与偏心的桥渡水流均可用该模型来计算。对于水流漫过引道路提以及用多孔桥跨越一个河谷的水力计算,无需预先假定每个桥孔的水流分布亦可进行。
The finite element method is used to derive the mathematical model describing the steady two-dimensional sluggishness of the bridge crossing in the area with large dense vegetation. Solving this water flow equation system by numerical method is combined to obtain the spatial distribution of water surface elevation and velocity for the specified boundary conditions within the flow area. The Galerkin weighted residue method is applied to the basic differential system to form the finite element notation. The cell shape selected for the model is triangular, the cell flow is defined as a quadratic function, and the water depth is defined as a linear function. For the orthogonal, skewed and eccentric cross-bridge flow can be calculated using this model. For hydraulic calculations that span waterways and span a valley with porous bridges, it is not necessary to assume that the water flow distribution at each bridge bore can be done in advance.