Hydraulic control of two-layer flow in “quadratic”-type channels
Hydraulic control of two-layer flow in “quadratic”-type channels
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“二次”型通道中双层流动的水力控制
DOI：
10.1080/00221686.2007.9521738
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发表时间：
2007
影响因子：
2.3
通讯作者：
P. Davies
中科院分区：
文献类型：
--
作者：
J. Laanearu;P. Davies
先前对矩形通道中两层交换流的处理已扩展到考虑通道几何形状对此类流动的水力学的影响。人们的注意力集中在“二次”通道中的交换流，“二次”通道定义为在表面具有单一宽度最大值 w0 和单一深度最大值 D（不一定位于通道横截面中心）的流动横截面。分析表明，通道横截面几何形状的影响可以用形状参数 Ψ 来令人满意地量化，形状参数 代表通道的横截面积与具有相同 w0 和 D 值的等效矩形通道的横截面积之比。具体来说，分析表明，根据形状参数 ψ 对两个流体层的弗劳德数进行适当的定义，使得可以为复合弗劳德数制定常见的通用临界条件 G2 = 1。此外，将所谓的函数方法应用于此类渠道问题已被证明与已经针对矩形渠道进行深入研究的两个参考示例（水平收缩和窗台）的水力模型结果显示出良好的定量一致性。最后，分析了沿河道方向 ψ 变化对交换流量的影响。
Previous treatments of two-layer exchange flow in a rectangular channel have been extended to consider the effects of channel geometry upon the hydraulics of such flows. Attention has been focussed on exchange flows in “quadratic” channels, defined as flow cross-sections having a single width maximum w0 at the surface and a single depth maximum D (not necessarily located at the centre of the channel cross section). The analysis shows that the effects of channel cross sectional geometry can be quantified satisfactorily in terms of a shape parameter ξ representing the ratio of the cross-sectional area of the channel to that of the equivalent rectangular channel having the same values of w0 and D. Specifically, the analysis shows that suitable definitions of the Froude numbers of the two fluid layers in terms of the shape parameter ξ enables the familiar general criticality condition G2 = 1 to be formulated for the composite Froude number. Furthermore, the application of the so-called functional approach to this type of channel problem is demonstrated to show excellent quantitative consistency with the results of the hydraulic model for two reference examples (the horizontal constriction and the sill) already studied intensively for rectangular channels. Finally, an analysis is presented to show the effects upon the exchange flow of changes in ξ in the along-channel direction.