Breakage and coalescence models for drops in turbulent dispersions

A substantial effort has been made by numerous investigators to describe droplet breakage and coalescence in turbulent dispersions. An attempt is made here to improve these models based on existing frameworks and recent advances described in the literature. Two‐step mechanisms are considered for both the breakage and coalescence models. The drop breakage function is structured as the product of the drop‐eddy collision frequency and breakage efficiency which reflect the energetics of turbulent liquid‐liquid dispersions. The coalescence function retains the former structure of the product of drop‐drop collision frequency and coalescence efficiency. The coalescence efficiency model has been modified to account for the effects of film drainage for drops with partially mobile interfaces. These models overcome several inconsistencies observed in previous efforts and are applicable for dense dispersions (about ϕ[0.10–0.30]). For the daughter drops produced by breakage, a probability density is proposed based on the energy requirements for the formation of daughter drops.