Effect of convective transport on droplet spinodal decomposition in fluids

Kumaran, V (1998) Effect of convective transport on droplet spinodal decomposition in fluids. In: Journal of Chemical Physics, 109 (6). pp. 2437-2441.

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Abstract

The effect of convective transport on the late stage growth of droplets in the presence of sedimentation and shear flow is analyzed. The high Peclet number limit (UR/D)$\gg$1 is considered, where U is the characteristic velocity, R is the radius of the droplet, and D is the diffusion coefficient. The growth of the droplet depends on the boundary condition for the fluid velocity at the droplet interface, and two types of boundary conditions are considered. For a rigid interface, which corresponds to the interface between a solid and a fluid, the tangential velocity is zero and the normal velocity is equal to the velocity of the surface. For a mobile interface, which corresponds to an interface between two fluids, the tangential and normal velocities are continuous. These results indicate that the scaling relations for the critical radius are $R_c(t)\alpha t^{(1/2)}$ for a sedimenting droplet with a rigid interface, $R_c(t)\alpha t^{(2/3)}$ for a sedimenting droplet with a mobile interface, $R_c(t)\alpha t^{(3/7)}$ for a droplet with a rigid interface in a simple shear flow, and $R_c(t)\alpha t^{(1/2)}$ for a droplet with a mobile interface in a simple shear flow. The rate of droplet growth is enhanced by a factor of $P_e^{(1/3)}$ for rigid interfaces and $P_e^{(1/2)}$ for mobile interfaces.

Item Type:	Journal Article
Publication:	Journal of Chemical Physics
Publisher:	AIP
Additional Information:	Copyright of this article belongs to The American Institute of Physics.
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	27 Nov 2006
Last Modified:	19 Sep 2010 04:32
URI:	http://eprints.iisc.ac.in/id/eprint/8973

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