Journal of Fluid Mechanics

Super-critical withdrawal from a two-layer fluid through a line sink if the lower layer is of finite depth

G. C. HOCKING a1 and L. K. FORBES a2
a1 Mathematics and Statistics, DSE, Murdoch University, Murdoch, Western Australia, 6150, Australia
a2 School of Mathematics and Physics, University of Tasmania, GPO Box 252-237, Hobart, 7001, Tasmania, Australia


The steady response of a fluid consisting of two regions of different density, the lower of which is of finite depth, is considered during withdrawal. Super-critical flows are considered in which water from both layers is being withdrawn, meaning that the interface is drawn down directly into the sink. The results indicate that if the flow rate is above some minimum, the angle of entry of the interface depends more strongly on the relative depth of the sink than on the flow rate. This has quite dramatic consequences for the understanding of selective withdrawal from layered fluids.

(Received January 29 1998)
(Revised August 15 2000)