An Enhanced Depth-integrated Model for Flows over a Negative Step with Hydraulic Jump
An Enhanced Depth-integrated Model for Flows over a Negative Step with Hydraulic Jump
复制标题
具有水跃的负台阶上流动的增强深度积分模型
DOI：
10.1051/e3sconf/20184005017
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T
中科院分区：
文献类型：
--
作者：
Uchida;T
深度积分模型在水流预报中具有重要的应用价值。有许多贡献，以发展一个增强的深度集成模式，有能力评估垂直流结构。然而，它仍然是具有挑战性的深度集成模型计算的流量超过一个负台阶伴随着水跃，因为后面的分离区和水跃的模式取决于几个水力条件，如弗劳德数，台阶高度和下游水深。在这项研究中，假设砾石床河流，其中床被覆盖有相对较大的粗糙度，一个增强的深度集成模型来计算各种下游产生的水跃模式的负步骤。该方法基于采用四次多项式速度分布的动力壁定律的通用底部速度计算方法（GBVC 4-DWL）。通过与负台阶淹没射流流场的实验结果对比，验证了负台阶后虚拟底坡和波浪破碎临界底坡模型的正确性。弱跳跃和波动跳跃条件。然后对构成本方法的方程组中的基本项进行了研究，以计算负台阶下游的流动。
Depth-integrated models play an important role of predicting flows for several practical problems. There are many contributions to develop an enhanced depth-integrated model to have the ability of evaluating vertical flow structures. However, it is still challenging for the depth integrated models to calculate flows over a negative step accompanying a hydraulic jump, because the separation zone behind the step and the pattern of the hydraulic jump depend on the several hydraulic conditions such as Froude number, step height and downstream water depth. In this study, assuming gravel bed rivers in which the bed is covered with relatively large roughness, an enhanced depth integrated model is developed to calculate various hydraulic jump patterns generated downstream from the negative step. The present method is based on General Bottom Velocity Computation method employing Dynamic Wall Law with 4th degree polynomial velocity distribution (GBVC4-DWL). The model with the virtual bed slope behind the negative step and the critical slope of wave breaking is validated through the comparisons with the experimental results on flows over a negative step for submerged jet. weak jump and undular jump conditions. Then the essential terms of equations which compose the present method to calculate the flow downstream of the negative step are investigated.