Comparison of turbulent drop breakup in an emulsification device and homogeneous isotropic turbulence: Insights from numerical experiments

Abstract

Turbulent emulsification is of considerable industrial interest. Nevertheless, numerical experiments (direct numerical simulations, DNS, with highly resolved interface tracking) have been mainly used to study drop breakup in idealized flows. This study, therefore, compares drop breakup in two different settings (homogenous and isotropic flow, and a simplified high-pressure homogenizer) with the intention of better understanding how insight gained from the idealized systems can be applied to industrially relevant devices. The flow differs between the two cases, with highly anisotropic and inhomogeneous turbulence in the latter. Results show similarities between the two cases regarding morphology of breakup, suggesting that the underlying mechanism, as a function of Weber number, is similar. However, differences are also observed, e.g., in terms of breakup time and deformed morphology, which are associated with the locality of the turbulence in the homogenizer. Implications for an improved understanding of turbulent breakup in industrially relevant devices are discussed.