Publications
Foam structure and rheology in thin gaps
The cell structure and rheology of gas-liquid foams confined between parallel plates depend on the ratio H/R, where H is the plate spacing and R is the (equivalent spherical) bubble radius. We consider ordered three-dimensional foams that consist of 1-3 layers of bubbles. In the 'dry' limit, where the gas fraction is unity, one confined layer is composed of hexagonal cylinders; two layers contain Fejes Toth cells; and three or more layers are modeled as Kelvin cells sandwiched between Fejes Toth cells. We also consider wet foams where all of the liquid is assumed to be located in either conventional Plateau borders or wall Plateau borders adjacent to the plates. The Surface Evolver is used to calculate the foam structure and stress as a function of H/R, which enables us to evaluate elastic behavior. A relationship between the two-dimensional structure at the wall and bubble size has application to foam characterization.