Prediction of the water distribution in a flowing foam

A two-dimensional mathematical model is presented which describes the time-averaged steady-state water distribution in a coalescing, flowing foam. The model uses previous work that predicts foam flow velocity and bubble coalescence. Drainage is described using the transient model of Verbist et al., extended into two-dimensions. The effect of coalescence is accommodated by introducing the concept of Plateau border length for each bubble. The formulation and solution technique of the highly non-linear partial differential equation is discussed in some detail. Simulations are shown that compare the water distribution for non-coalescing and coalescing foams. The model will have application for determining the liquid content of flowing foams, the entrainment of solids in flotation systems and for designing foam process equipment.