Mixing in a density-driven current flowing down a slope in a rotating fluid
MetadataShow full item record
We discuss laboratory experiments investigating mixing in a density-driven current flowing down a sloping bottom, in a rotating homogenous fluid. A systematic study spanning a wide range of Froude, 0.8 < Fr < 10, and Reynolds, 10 < Re < 1400, numbers was conducted by varying three parameters: the bottom slope; the flow rate; and the density of the dense fluid. Different flow regimes were observed, i.e. waves (non-breaking and breaking) and turbulent regimes, while changing the above parameters. Mixing in the density-driven current has been quantified within the observed regimes, and at different locations on the slope. The dependence of mixing on the relevant non-dimensional numbers, i.e. slope, Fr and Re, is discussed. The entrainment parameter, E, was found to be dependent not only on Fr, as assumed in previous studies, but also on Re. In particular, mixing increased with increasing Fr and Re. For low Fr and Re, the magnitude of the mixing was comparable to mixing in the ocean. For large Fr and Re, mixing was comparable to that observed in previous laboratory experiments that exhibited the classic turbulent entrainment behaviour.
Author Posting. © Cambridge University Press, 2008. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 604 (2008): 369-388, doi:10.1017/S0022112008001237.
Showing items related by title, author, creator and subject.
An experimental study of a mesoscale vortex colliding with topography of varying geometry in a rotating fluid Adduce, Claudia; Cenedese, Claudia (Sears Foundation for Marine Research, 2004-09)The interaction of a self-propagating barotropic cyclonic vortex with an obstacle has been investigated and the conditions for a vortex to bifurcate into two vortices determined. As in a previous study, after a self-propagating ...
Cenedese, Claudia; Adduce, Claudia; Fratantoni, David M. (American Geophysical Union, 2005-09-30)The present study investigates the interaction between a self-propagating cyclonic vortex with two right vertical cylinders and determines the conditions for a vortex to bifurcate into two or more vortices. As in previous ...
Cenedese, Claudia; Adduce, Claudia (American Meteorological Society, 2010-08)Dense overflows entrain surrounding waters at specific locations, for example, sills and constrictions, but also along the descent over the continental slope. The amount of entrainment dictates the final properties of these ...