a1 Mathematics and Statistics, DSE, Murdoch University, Murdoch, WA, 6150, Australia.
a2 Department of Mathematics, University of East Anglia, Norwich, UK.
a3 School of Mathematics and Physics, The University of Tasmania, Hobart, TAS 7001, Australia.
The problem of withdrawal through a point sink of water from a fluid of finite depth with a free surface is considered. Assuming the flow to be axisymmetric, it is found that there is a maximum Froude number at which such flows can exist. This maximum corresponds to the formation of a secondary stagnation ring on the free surface. This result extends earlier work on this problem. Comparison is made with a small Froude number solution and past experimental results.
(Received September 21 1998)
(Revised September 03 1999)