Simple wave and monoclinal wave models: River flow surge applications and implications
Simple wave and monoclinal wave models: River flow surge applications and implications
复制标题
简单波浪和单斜波模型：河流涌动应用和影响
DOI：
10.1029/2004wr003923
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发表时间：
2005
影响因子：
5.4
通讯作者：
M. G. Ferrick
中科院分区：
文献类型：
--
作者：
M. G. Ferrick
河流中的不稳定流量波动可以理想化为下游稳定流量较低和上游稳定流量较高之间的过渡。简单波和单斜波模型是动态波动方程的解析解，可用于模拟这些浪涌。简单的波浪模型忽略了河床坡度和流动阻力，模拟了相对较短距离内的浪涌传播。单斜波轮廓逐渐演化，该模型通常适用于较大距离。这些模型易于使用，通常适用于不同的流动条件。然而，这两种模型都缺乏确定其是否适合特定应用的标准。本文的目的是制定和评估指导简单波和单斜波模型应用的标准，并使用这些模型来深入了解惯性和坡流阻力对动量的贡献以及增加浪涌幅度的非线性效应。简单波浪模型应用标准包括无量纲时间、向下游行进的线性动态波的振幅与初始振幅之比、距离尺度以及测量的浪涌速度与高流量上游的c+动态波速度之间的比率。单斜扩散波轮廓的长度给出了形成稳定单斜波轮廓所需的最小距离。使用涵盖各种条件的实验室和现场研究的数据来评估描述流量波动的模型能力和应用标准的充分性。由于不存在斜率和流阻效应，简单波的轮廓速度和浪涌后面的高流速总是大于单斜波。模型之间的差异随着弗劳德数的减小和浪涌幅度的增大而增强。
Unsteady flow surges in rivers can be idealized as a transition between lower steady flow downstream and higher steady flow upstream. Simple wave and monoclinal wave models are analytical solutions of the dynamic wave equations that can be used to model these surges. The simple wave model neglects bed slope and flow resistance, simulating surge propagation over relatively short distances. The monoclinal wave profile evolves progressively, and this model is generally applicable at larger distances. These models are easy to use and generally apply to different flow conditions. However, both models lack criteria to determine their suitability for specific applications. The objectives of this paper are to develop and to assess criteria to guide simple wave and monoclinal wave model applications and to use the models to gain insights into the inertia and slope–flow resistance contributions to momentum and the nonlinear effects of increasing surge amplitude. Simple wave model application criteria include a dimensionless time, the amplitude to initial amplitude ratio for a linear dynamic wave traveling downstream, a distance scale, and the ratio between the measured surge celerity and the c+ dynamic wave celerity of the high flow upstream. The length of the monoclinal‐diffusion wave profile gives the minimum distance needed to develop a steady monoclinal wave profile. Model capabilities to describe flow surges and the adequacy of the application criteria are evaluated with data from laboratory and field studies covering a wide range of conditions. Profile celerity and high flow velocity behind the surge are always greater for the simple wave than for the monoclinal wave because of the absence of slope and flow resistance effects. The differences between the models are enhanced as Froude number decreases and as surge amplitude increases.