Liquid films with high surface modulus moving in tubes: Dynamic wetting film and jumpy motion

We investigate the motion of transverse soap films, or lamellae, of high surface dilatational modulus through a wet tube. Combining local thickness and velocity measurements in the wetting film, we reveal a zone several centimeters in length, the dynamic wetting film, which is significantly influenced by a moving lamella. The dependence of this influence length on lamella velocity and wetting film thickness provides discrimination among several possible surfactant minimal models. A spectacular jumpy mode of the unsteady motion of a lamella is also evidenced.