  When two immiscible liquids that coexist inside a porous medium are drained
through an opening, a complex flow takes place in which the interface between
the liquids moves, tilts and bends. The interface profiles depend on the
physical properties of the liquids and on the velocity at which they are
extracted. If the drainage flow rate, the liquids volume fraction in the
drainage flow and the physical properties of the liquids are known, the
interface angle in the immediate vicinity of the outlet (theta) can be
determined. In this work, we define four nondimensional parameters that rule
the fluid dynamical problem and, by means of a numerical parametric analysis,
an equation to predict theta is developed. The equation is verified through
several numerical assessments in which the parameters are modified
simultaneously and arbitrarily. In addition, the qualitative influence of each
nondimensional parameter on the interface shape is reported.
