On the mathematical modelling of 2D fluid foams

Fluid foams are two-phase fluids with a great variety of textures which may change during their deformation processes. Their continuum mechanical modelling is made problematic by the difficulty of individuating what to regard as a material point. In Part 1, the simplest shearing motion of a monodisperse, close-packed, two-dimensional fluid foam is here revisited. In Part 2, the notion of a foamy continuum, that is, an ordinary continuum body imitating the foam’s behaviour, is introduced. The final section contains a brief discussion of the thermodynamics of a shear deformation process involving a topological change of texture.