Abstract
A theoretical model was proposed to consider the dynamic contact angle from a macroscopic viewpoint. A slight convex profile of liquid surface is assumed to avoid the divergence of viscous stress near the three-phase contact line on the wall. The theoretical results of the dynamic contact angle are dependent on the parameter ε, i.e., the ratio of surface area occupied by the defects on the solid surface. The movement of liquid column in a capillary is investigated experimentally. The modified Lucas-Washburn equation including the effect of dynamic wetting represents well the measured results. The theoretical model can approximate the measured dynamic contact angles within the experimental uncertainty.
