CAPILLARY RISE IN A NON-UNIFORM TUBE

In this paper we describe the liquid progression in a non-uniform capillary in the case where the inertia effects are considered. The approach is based on the application of Newton's second law on the liquid column. Numerical solutions are obtained by solving a general differential equation describing the time-dependent rise of the liquid gas interface. The effect of capillary geometry on the progress of the liquid interface has been investigated in conical and sinusoidal capillaries while varying several parameters, such as cone opening angle a in both converging and diverging tubes and the undulation of a sinusoidal capillary. The influence of inertia and viscosity on the equilibrium height and on the rise dynamics is investigated. The results allow better comprehension of the capillary rise in complex geometry under inertia effects and these might provide further explanation for fluid distribution in modeled porous media.