Rotating exchange flows through straits with multiple channels: Preliminary results of laboratory studies
Rotating exchange flows through straits with multiple channels: Preliminary results of laboratory studies
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多渠道海峡的轮换交换流：实验室研究的初步结果
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
D. Smeed
中科院分区：
文献类型：
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作者：
B. Rabe;D. Smeed
世界大洋的深盆地被海脊和海岸隔开，盆地之间的交换发生在流经基岩和海峡的流动中。海峡和海床上的动态过程控制着交易所的价值。因此，这些地形特征对海洋的大范围温盐环流有相当大的影响，因此对气候也有相当大的影响。许多宽阔的海峡由多个由岛屿隔开的海峡组成，预计旋转是重要的。该项目的目标是：1)量化平底海峡的交换通量，并与现有理论进行比较。2)确定岛屿对交换流量的定性和定量影响。旋转液压流比非旋转等效流要复杂得多；尤其是在液压控制方面。通道的加宽导致较高的罗斯比数(罗斯比半径与通道宽度之比)的流量更大。模拟旋转两层海峡交换的实验是在格勒诺布尔的大型科里奥利转盘上实现的。对于小于1的Rossby数，我们证实了以前的发现，即通量近似地与通道宽度无关，并且仅受旋转的限制。该岛显著影响这一行为，特别是通过缩小海峡宽度相对于Rossby数标度，从而增加流量相对于简单的通道当量在相同的旋转。此外，在孤岛和简单通道的流场中发现了许多定性的差异，特别是在通道内交换电流的路径方面。
The deep basins of the world’s oceans are separated by ridges and coasts, and the exchange between basins occurs in flow over sills and through straits. Dynamical processes in the straits and sills control the value of the exchanges. Thus these topographic features have a considerable impact upon the large-scale thermohaline circulation of the ocean, and hence upon climate. Many wide straits, where rotation is expected to be important are composed of multiple channels separated by islands. The project objectives are: 1) To quantify the exchange flux through a flat-bottomed strait and compare with existing theory. 2) Determine the qualitative and quantitative effects of an island on the exchange flow. Rotating hydraulic flows are more complicated than the non-rotating equivalent; in particular with respect to hydraulic control. Widening of the channel leads to a greater flux for high Rossby numbers (ratio of Rossby radius to channel width). Experiments to model a rotating two-layer strait exchange were realised on the large Coriolis turntable in Grenoble. For Rossby numbers less than unity, we confirm previous findings that the flux is approximately independent of channel width and only constrained by rotation. The island significantly influences this behaviour by, in particular, by narrowing the strait width with respect to the Rossby number scaling and thus increasing the flux relative to the simple channel equivalent at the equal rotation. Furthermore, many qualitative differences were found in the flow field between the island and simple channel cases, in particular with respect to the path of the exchanging current within the channel.