A Model for the Viscous Coalescence of Amorphous Particles

A model is presented for coalescence by viscous flow in two-particle systems, a phenomenon of interest in such diverse processes as the coagulation of air pollutant aerosols, glass and polymer sintering, and the coagulation of liquid suspensions. The model achieves computational efficiency by incorporating an empirical analytical function to describe the fluid interface, making it particularly suited to incorporation into aerosol dynamics models under conditions where coalescence-limited growth can occur. The dynamics of the interfacial evolution in the coalescing pair are approximated by employing a modification to the boundary integral approach in which a single surface point is used to solve the equations for the surface velocities. Model predictions of dimensionless shrinkage and neck growth obtained using this modeling approach compare favorably to those of existing finite-element models reported in the literature and provide a basis for more complex models to approximate multiple particle coalescence.