Influence of hydrodynamic forces and interfacial momentum transfer on the flow of two immiscible phases

Conventional theory regarding immiscible two-phase flow neglects the effect that hydrodynamic forces and interfacial momentum transfer have on flow through porous media. The significance of such neglect is explored by estimating the relative error incurred when these effects are neglected. It is shown, by investigating several one-dimensional problems, that relative errors of about 1% are incurred by neglecting the effect of the hydrodynamic forces, whereas errors of about 40% are introduced when viscous coupling across fluid–fluid interfaces is neglected.