Transient convective mass transfer for a fluid sphere dissolution in an alternating electric field

In this study, we considered mass transfer in a binary system comprising a stationary fluid dielectric sphere embedded into an immiscible dielectric liquid under the influence of an alternating electric field. Fluid sphere is assumed to be solvent-saturated so that an internal resistance to mass transfer can be neglected. Mass flux is directed from a fluid sphere to a host medium, and the applied electric field causes a creeping flow around the sphere. Droplet deformation under the influence of the electric field is neglected. The problem is solved in the approximations of a thin concentration boundary layer and finite dilution of a solute in the solvent. The thermodynamic parameters of a system are assumed constant. The nonlinear partial parabolic differential equation of convective diffusion is solved by means of a generalized similarity transformation, and the solution is obtained in a closed analytical form for all frequencies of the applied electric field. The rates of mass transfer are calculated for both directions of fluid motion-from the poles to equator and from the equator to the poles. Numerical calculations show essential (by a factor of 2/3) enhancement of the rate of mass transfer in water droplet-benzonitrile and droplet of carbontetrachloride-glycerol systems under the influence of electric field for a stagnant droplet. The asymptotics of the obtained solutions are discussed. (C) 2004 Elsevier Ltd. All rights reserved.