Role of Wettability in the Break-Up of Liquid Films inside Constricted Capillaries

摘要

To understand the role of wettability on gas-foam generation in porous media, this work considers the effect of conjoining/disjoining pressure on the dynamics of a liquid film forming an unstable collar in both straight and constructed cylindrical capillaries. A hydrodynamic lubrication analysis is presented to describe the time evolution of a thin viscous film under the influence of surface tension and the conjoining or disjoining forces. Time to break-up depends on the pore shape, the strength of the conjoining/disjoining forces, the initial film thickness, and also, on the fluid viscosity, interfacial tension, and unconstricted pore radius which combine to form a characteristic scaling time. Results show that both conjoining (intermediate wettability) and disjoining (strongly wetting) forces inhibit break-up. 33 refs., 9 figs., 1 tab. (ERA citation 12:007927)