Modeling overfalls using vertically averaged and moment equations
Modeling overfalls using vertically averaged and moment equations
复制标题
使用垂直平均方程和力矩方程对溢流进行建模
DOI：
10.1061/(asce)0733-9429(1996)122:7(397
复制
发表时间：
1996
影响因子：
2.4
通讯作者：
P. Steffler
中科院分区：
文献类型：
--
作者：
A. A. Khan;P. Steffler
一组新的垂直平均和力矩方程，假设一个线性的纵向速度分布和二次垂直速度和压力分布，用于模拟附近的水平矩形自由溢流与光滑和粗糙的床和尖顶堰与倾斜的上游面。这些方程建模使用混合彼得罗夫-伽辽金和Bubnov-Galerkin有限元格式。对于矩形自由溢流，预测的溢流上游水面线和自由射流轨迹与实测数据吻合较好。计算的垂直速度和压力分布的边缘和上游的溢流被发现是在良好的协议与实测数据，而计算的纵向速度分布比较以及与二维势流模型。上游面倾斜的尖顶堰的计算结果与上游堰坡与水平面成27°时的实测数据吻合较好。对于45°和更陡的上游坡度以及大堰高，堰上游的预测水面显示出数值不稳定性。
A new set of vertically averaged and moment equations, which assumes a linear longitudinal velocity distribution and quadratic vertical velocity and pressure distributions, is used for modeling flow in the vicinity of horizontal rectangular free overfall with smooth and rough beds and sharp-crested weirs with sloping upstream faces. These equations are modeled using a hybrid Petrov-Galerkin and Bubnov-Galerkin finite-element scheme. For the rectangular free overfalls, the predicted water surface profiles upstream of the overfall and the free jet trajectory agree well with the measured data. The computed vertical velocity and pressure distributions at the brink and upstream of the overfall are found to be in good agreement with the measured data; while the computed longitudinal velocity distributions compare well with a two-dimensional potential flow model. The computed results for sharp-crested weirs with sloping upstream faces agree well with the measured data for an upstream weir slope of up to 27° with the horizontal. For an upstream slope of 45° and steeper and for a large weir height the predicted water surface upstream of a weir shows numerical instability.