Effect of polydispersity on the structural characteristics of two-phase foam

Two-phase foam fluid in a two-dimensional pattern is easily observable in our life and industrial applications. In this study, a series of quasi-equilibrium foam structures are built based on minimum energy principle. We then focus on the dispersity of bubble size and investigate its influence on the structural characteristics of the foam, including foam interface length, interface energy, average bubble pressure and bubble coordination number. All of these foam parameters are normalized here. Principally, we find that both the total interface lengths of the dry and the wet foams reduce linearly with increasing polydispersity. As the liquid fraction is lower than the wet limit, the interface energy decreases and the average bubble pressure rises with the increase of the polydispersity, while at higher liquid fraction, their values are approximately constant and the link between each of them and the polydispersity is expressed by the empirical equations. In addition, the dependence of the average coordi-nation number on the polydispersity is not particularly evident. Our study can provide reference for under-standing the structure of the two-phase foam, as well as guidance for designing a two-dimensional foam pattern.