Numerical modelling of foam Couette flows
Résumé
We present a numerical simulation based on a tensorial elastoviscoplastic model that includes a viscous drag and compare it to experimental measurements on liquid foams trapped between two glass plates in a bidimensional cylindrical Couette geometry, both in stationary and transient regimes. The main features of the model are elasticity up to a plastic yield stress and viscoelasticity above. The numerical modelling bases on a small set of standard material parameters that could be fully characterised. Shear localisation as well as fine transient observations are reproduced and are found to be in good agreement with experimental measurements. The plasticity appears to be the fundamental mechanism of the localisation of the flow. The present approach can be extended from liquid foams to similar materials such as emulsions, colloids or wet granular materials that exhibit localisation.