Numerical models of two-phase electrohydrodynamics for simulating key processes in electrostatic coalescers: a review (invited paper)

This review article aims to describe and compare widely used numerical models for the computer simulation of key electrohydrodynamic processes occurring in electrostatic coalescers, as well as to present the main results obtained using these models. Both pairwise droplet interaction models and multi-droplet models are considered. The former are based on tracking the movement of the interfacial boundary and employ approaches such as the phase-field, conservative level-set, coupled level-set and volume of fluid, arbitrary Lagrangian–Eulerian, isoAdvector, and boundary element (or integral) methods. The latter rely on a macroscopic description of emulsion evolution via the population balance model or by solving the equations of motion for a collection of droplets. In addition, the review includes models based on the molecular dynamics method. For each model, its capabilities, advantages, disadvantages, and limitations are described, along with the possible types of results obtained and corresponding examples.

The results obtained address issues such as the threshold transition from coalescence to non-coalescence in droplet-droplet and droplet-layer systems, partial coalescence and the regime map of non-coalescence, as well as the interrelation of results derived from different types of models.