Micro-mechanical prediction of the effect of surfactant concentration and external friction on the visco-elasto-plastic response of an aqueous foam.

We apply a combination of the Viscous Froth model and a surfactant transfer model [Zaccagnino et al., Phys. Rev.

Simulation of surfactant transport during the rheological relaxation of two-dimensional dry foams.

We describe a numerical model to predict the rheology of two-dimensional dry foams. The model accurately describes soap film curvature and viscous friction with the walls, and includes the transport of surfactant within the films and across the vertices where films meet. It accommodates the changes in foam topology that occur when a foam flows and, in particular, accurately represents the relaxation of the foam following a topological change.