A NETWORK SIMULATION FOR DRAINAGE OF STATIC FOAM COLUMNS

A simple cylindrical network consisting of regular hexagons is used to simulate the flow during drainage in a static foam column. The dimensions of the network are calculated by considering the foam to consist of regular pentagonal dodecahedral bubbles. Simulations offer several new insights concerning the microscopic origin of the nonlinearity and inflection in the drainage plot. It is shown that the contraction of Plateau border channels in the presence of bubbles of varying sizes causes the observed nonlinearity in the drainage plot. Inflection in the drainage plot can be observed only when the liquid volume fraction increases with column height. Other calculations concerning the effects of bubble size and column height are consistent with experimental observations.