Author(s): Greg Lawrence
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Keywords: No Keywords
Abstract: This paper investigates the instability of the interface in the gravitational exchange of two-fluids of slightly different density through a contraction of uniform depth and gradually varying width. The hydraulic solutions of Armi and Farmer (1986) for a moderately barotropic exchange flow are shown to give values of the stability Froude number of up to 2.0. This is significant since Long (1956) show that long internal waves are unstable if the stability Froude num ber is greater than unity. It is more relevant, however, to consider the behaviour of short wave ins tabilities, e. g., the Kelvin-Helm holtz instability. Experiments on the stability of two-layer shear flows indicate that the mixing caused by Kelvin-Helmholtz instabilities increases with increasing stability Froude number. This mixing may compromise the assumption of a layered flow, but at least for values of the stability Froude number up to 2 the flow is not likely to be totally disrupted.
Year: 1989