Dynamics of foams with and without wall rupture

A physically based model for the evolution of dry, two-dimensional foams based on a combination of mass transfer, vertex movement, and edge relaxation, enables efficient and accurate simulation with and without wall rupture. The stochastic nature of topological transitions due to numerical error has been carefully examined and may explain the discrepancies found among various simulations. The separation of vertex and edge movements permits a study of foam evolution that includes wall rupture. Comparison with recent experimental results is presented that demonstrates that certain, semiempirical ''breaking rules'' are capable of reproducing both the overall topological evolution and certain scaling behavior observed in the experiments.