I. Cantat – 7 mai

The highly confined flow of the liquid phase, trapped between the gas bubbles, is at the origin of the large effective viscosity of the liquid foams. Despite the industrial relevance of this complex fluid, the foam viscosity remains difficult to predict, because of the lack of flow characterization at the bubble scale. Using an original deformable frame, we measure the film thickness and velocity maps during the film deformation, and evidence a complex competition between film stretching/compression, film shearing, and volume exchange with the menisci bounding the film. Using hydrodynamical models, we show the crucial role of the deformable interfaces and of the Marangoni stress in this problem.