Slip effects on forced dewetting

The forced dewetting of a viscous liquid confined in a cylindrical
tube of radius r_o is studied for a wide range of slip length b
using the boundary element method. For b << r_o, the classical
logarithmic relation (weak effect) between the critical velocity (U_c) of
entrainment and the slip length is recovered. However, when increasing the slip
length, we demonstrate a crossover from the logarithmic relation to a
regime where U_c scales linearly with b for b >> r_o. We explain this behaviour in terms of
a change of the flow structure inside the liquid. Namely, for b << r_o, shear stress is the
dominant force, which is inversely proportional to the distance from the contact line, e.g. 1/r.
For b >> r_o, a plug flow is generated with stresses that scale as 1/b. In this
regime, the energy input to the system is mainly dissipated by the
friction at the solid/liquid boundary.