Massively Parallelised Interface-Tracking Simulations of Two-Phase Mixing Flows

We study a complex turbulent multiphase mixing problem using a numerical framework that considers fluid-structure interaction. Flow mixing inside a stirred vessel occurs in a vast array of industrial applications and produces complex dynamical structures for both single and multiphase mixing model. These dynamical structures can influence both the mixing efficiency and the final quality of the mixed product. Understanding the behaviour occurring in such configurations is very important in terms of being able to rapidly optimise mixing and to better engineer designs for the desired output.

In this project, we are interested in the interaction of a solid rotating mixer (impeller) with two-phase flow dynamics in an established cylindrical setting representative of many chemical processes. In such a study, the free-surface deformation and vortical flow formed by the action of the impeller rotation is studied. At a critical rotation rate (here, 11 Hz) the air is vigorously entrained in the liquid with the formation of numerous bubbles of varying size as shown in the figure. With such direct numerical simulations, we hope to enable an increased fundamental understanding of this highly non-linear and complex multiscale flow.