Buoyancy-driven unbalanced exchange flow through a horizontal opening
Buoyancy-driven unbalanced exchange flow through a horizontal opening
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浮力驱动的不平衡交换流通过水平开口
DOI：
10.1017/jfm.2020.55
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发表时间：
2020
影响因子：
3.7
通讯作者：
Wise N
中科院分区：
文献类型：
--
作者：
Wise N
浮力驱动的交换流发生在各种自然和工业环境中，包括核能和水利工程、海洋学和建筑通风。平衡交换流，即同时有等量通量通过一个水平开口垂直向上和向下传递，以前已经在理论上描述过。然而，到目前为止，还没有理论描述不平衡交换流，即通过开口的一个方向的体积通量超过另一个方向的体积通量。本文开发的模型考察了在水平面上的一个开口处密度界面上扰动的增长，该开口连接了下面的浮力流体和上面的致密流体。通过考虑界面被垂直方向施加的大量流动从开口平面平流，我们量化了不平衡情况下的交换。该模型成功地预测了弗劳德数准则，该准则直接对应于施加流量的最小无因次流量，用于实验中发现的圆开口间不平衡交换的开始。此外，对预测和测量的交换进行的比较表明，在整个可能的流动范围内，从单向流动到不平衡交换再到平衡交换，都非常一致。考虑了该模型在海洋排水口设计和建筑物通风流量预测中的应用。对于自然通风，我们推导的不平衡交换的理论模型弥补了位移流（其中流动是单向的）和平衡交换流之间预测空气流速的差距。
Buoyancy-driven exchange flows occur in a variety of natural and industrial situations, including nuclear and hydraulic engineering, oceanography and building ventilation. Balanced exchange flows, whereby there is simultaneously an equal volume flux transferred vertically upwards and downwards through a horizontal opening, have previously been described theoretically. However, until now there has been no theoretical description of unbalanced exchange flows, whereby the volume flux in one direction through an opening exceeds that in the other. The model developed herein examines the growth of perturbations on the density interface at an opening made in a horizontal plane that connects buoyant fluid below with denser fluid above. By considering the interface as it is advected away from the plane of the opening by a bulk flow imposed in the vertical, we quantify the exchange for the unbalanced case. The model successfully predicts the Froude number criterion, which corresponds directly to the minimum dimensionless flow rate of the imposed flow, for the onset of unbalanced exchange across circular openings found experimentally. Additionally, comparisons made between the exchanges predicted and measured show excellent agreement across the entire range of possible flows, from unidirectional flow, through unbalanced exchange to balanced exchange. Consideration is given to applications of the model to ocean outfall design and to the prediction of building ventilation flows. For natural ventilation, the theoretical model we derive for unbalanced exchange bridges the gap in the prediction of air flow rates between displacement flows, where the flow is unidirectional, and balanced exchange flows.
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DOI：
--
发表时间：
1988
期刊：
影响因子：
--
作者：
D. L. Wilkinson
通讯作者：
D. L. Wilkinson
浮力驱动的交换流通过液体罐中水平隔板的密度分层
DOI：
--
发表时间：
2001
期刊：
影响因子：
--
作者：
S. Kuhn;R. Bernardis;C. Lee;P. Peterson
通讯作者：
P. Peterson
影响因子：
--
作者：
T. Conover;Ranganathan Kumar;J. Kapat
通讯作者：
T. Conover;Ranganathan Kumar;J. Kapat
地中海交换流量对欧洲时间平均海平面的影响
影响因子：
5.2
作者：
Hughes C
通讯作者：
Hughes C
影响因子：
3.7
作者：
BAINES, WD;TURNER, JS
通讯作者：
TURNER, JS