MASS-TRANSFER AROUND A MOVING ENCAPSULATED LIQUID-DROP

The characteristics of forced-convection mass transfer around a moving gas-liquid compound encapsulated drop, assumed to be spherical and concentric, are studied numerically under the condition of uniform concentration at the outer interface. Numerical solutions of the Navier-Stokes equations and the diffusion equation including the first-order chemical reaction term have been obtained up to Re = 200. The effects of the inner and outer radii of the encapsulated drop, the physical properties of the fluids and the chemical reaction rate on the mass transfer coefficient are investigated quantitatively. The dependence of the concentration contours on the streamlines around the encapsulated drop is discussed in detail. Results of numerical predictions of the mass transfer coefficient are compared with previous results of the same for a gas bubble, for a liquid drop and for a rigid sphere. The work suggests the possibility of highly functional mass exchange by applying encapsulated drops as spherical liquid membranes.