Equation of motion of the triple contact line along an inhomogeneous surface

Wetting flows are controlled by the contact line motion. We derive an equation that describes the slow time evolution of the triple solid-liquid-fluid contact line for an arbitrary distribution of defects on a solid surface. The capillary rise along a partially wetted infinite vertical wall is considered. The contact line is assumed to be only slightly deformed by the defects. The derived equation is solved exactly for a simple example of a single defect. Introduction.