Journal of Fluid Mechanics

A spherical particle straddling a fluid/gas interface in an axisymmetric straining flow

J. A.  Stoos a1p1 and L. G.  Leal a1p2
a1 Department of Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA

Article author query
stoos ja   [Google Scholar] 
leal lg   [Google Scholar] 


Numerical solutions, obtained via the boundary-integral technique, are used to consider the effect of a linear axisymmetric straining flow on the existence of steady-state configurations in which a neutrally buoyant spherical particle straddles a gas–liquid interface. The problem is directly applicable to predictions of the stability of particle capture in flotation processes, and is also of interest in the context of contact angle and surface tension measurements. A primary goal of the present study is a determination of the critical capillary number, Cac, beyond which an initially captured particle is pulled from the interface by the flow, and the dependence of Cac on the equilibrium contact angle θc. We also present equilibrium configurations for a wide range of contact angles and subcritical capillary numbers.

(Published Online April 26 2006)
(Received May 4 1989)
(Revised January 9 1990)

p1 Current address: Mobil R. & D., Paulsboro, New Jersey 08066, USA.
p2 Curent address: Department of Chemical and Nuclear Engineering, University of California at Santa Barbara, Santa Barbara, CA 93106, USA.