Modeling rapidly varied flow in tailwaters
Modeling rapidly varied flow in tailwaters
复制标题
对尾水中快速变化的流量进行建模
DOI：
10.1029/wr020i002p00271
复制
发表时间：
1984
影响因子：
5.4
通讯作者：
S. E. Long
中科院分区：
文献类型：
--
作者：
M. G. Ferrick;J. Bilmes;S. E. Long
理解相对短周期的尖锋、大振幅波的下游传播对于描述水电站尾水中快速变化的水流和大坝溃决后的水流是很重要的。首先确定主要的物理过程，然后进行分析的解决方案，这些波的数值模型的开发。动态明渠水流方程的线性分析提供了描述河流中流波平流、扩散和弥散的关系。一个一维扩散波模型修改应用到尾水模拟重要的物理过程，是直接适用。修改后的方程和冯诺依曼分析提供了洞察数值参数θ，…三角洲x，和三角洲t的稳定性和耗散和色散行为的解决方案，但Hirt分析被发现产生不正确的相位关系。通过数值扩散与物理扩散相平衡，提高了模型的计算能力和精度。在两个完全不同的尾水进行了实地研究，以评估我们对大规模，快速变化的流波的理解。对具有广泛振幅、形状、周期和基流的波浪的精确模拟证明了模型的物理基础和数值解技术的合理性。这些研究表明，自然，自由流动的河流中的短周期波的扩散是显着的，惯性可以忽略不计。«少
An understanding of the downstream propagation of sharp-fronted, large-amplitude waves of relatively short period is important for describing rapidly varying flows in tailwaters of hydroelectric plants and following the breach of a dam. A numerical model of these waves was developed by first identifying the primary physical processes and then performing an analysis of the solution. A linear analysis of the dynamic open channel flow equations provides relationships describing flow wave advection, diffusion, and dispersion in rivers. A one-dimensional diffusion wave model modified for application to tailwaters simulates the important physical processes and is straightforward to apply. The modified equation and von Neumann analyses provide insight into the effects of numerical parameters theta, ..delta..x, and ..delta..t upon stability and dissipative and dispersive behavior of the solution, but the Hirt analysis is found to yield incorrect phase relationships. The capability and accuracy of the model are enhanced when physical diffusion of a river wave is balanced by numerical diffusion in the model. Field studies were conducted in two greatly different tailwaters to assess our understanding of large-scale, rapidly varying flow waves. The accurate simulation of waves having wide-ranging amplitudes, shapes, periods, and base flows attests to the soundness of both themore » physical basis of the model and the numerical solution technique. These studies reveal that diffusion of short-period waves in natural, free-flowing rivers is significant and that inertia is negligible.« less