On the Linear Encroachment in Two-Immiscible Fluid Systems in a Porous Medium

A careful review to the previous study of Srinivasan and Vafai on the linear encroachment in two-immiscible fluid systems in a porous medium reveals some typos in their analytical solution. In the present study, an accurate analytical solution, which accounts for boundary and inertia effects, is obtained to predict the movement of the interfacial front and corrections to previous results are provided wherever necessary. Despite the similarity in the general behavior of the present accurate solution and the previous one, the existence of an accurate analytical solution is essential for future numerical and experimental studies.