×

Heat, salt and momentum transport in a laboratory thermohaline staircase. (English) Zbl 1183.76029

Summary: Flow characteristics and fluxes in thermohaline staircases are measured in two tanks differing in aspect ratio A, where A is the ratio of tank width to fluid depth. In one tank (the ‘\(1 \times 1\)’ tank) which is 30 cm deep and 30 cm wide, a staircase of one salt-finger layer and one convecting layer develops for a certain setting of the control parameters. The convecting layer has \(A \simeq 2\). Shadowgraphs show convecting plumes that appear disorganized, and a large-scale flow never develops. Instead, the finger layer grows in height, overtakes the convecting layer and within a few days becomes one finger layer. The second tank (the ‘\(1 \times 5\)’ tank) is also 30 cm deep but is 150 cm wide. For the same control parameter setting a similar staircase with a finger layer 20 cm deep and a convecting layer 10 cm deep develop. The convecting layer, with \(A = 15\), has quite a different character. A large-scale flow develops so that the convecting layer has one cell, 10 cm deep and 150 cm wide. In this flow are large plumes which are transient and tilted; particle image velocimetry measurements of Reynolds stresses show they help to maintain the large-scale flow against viscous dissipation. Shadowgraphs show all the finger tips swept in the direction of the large-scale flow adjacent to the finger layer. Measurements show that the large-scale flow ‘collects’ the salt delivered by the many fingers so that the accumulated negative buoyancy leads to deep convection. This is a more stable arrangement, with the configuration lasting to the order of \(10^2\) days.

MSC:

76-05 Experimental work for problems pertaining to fluid mechanics
76R50 Diffusion
80A20 Heat and mass transfer, heat flow (MSC2010)
PDF BibTeX XML Cite
Full Text: DOI

References:

[1] Oster, Scient. Am. 213 pp 70– (1965)
[2] DOI: 10.1017/S0022112072000916
[3] DOI: 10.1073/pnas.78.4.1981
[4] DOI: 10.1016/0169-5983(95)00056-J
[5] DOI: 10.1017/S0022112003004166 · Zbl 1032.76505
[6] DOI: 10.1017/S0022112004002290 · Zbl 1065.76087
[7] DOI: 10.1017/S0022112080000511
[8] DOI: 10.1017/S0022112089001643
[9] Schmitt, J. Mar. Res. 37 pp 419– (1979)
[10] DOI: 10.1016/0198-0149(79)90013-X
[11] DOI: 10.1017/S002211200600992X · Zbl 1093.76511
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.