(371b) Liquid-Liquid Dispersions: Modeling across Length Scales Using Eulerian-Lagrangian Conversion

Liquid-liquid dispersions are abundant across many industries; these include food emulsions, cosmetic creams, pharmaceutical products, and many more. Many systems that produce these dispersions receive two separate immiscible liquids as input, then use mechanical energy to break up one phase into small droplets. Modeling these systems using CFD can aid in optimization, but the large range of scales involved is challenging to model. The system can initially be modeled with an Eulerian approach as the interface between the immiscible phases is on the macroscopic scale. At the end of the process, Lagrangian particles best capture the state of the system since the dispersed phase has been broken up into microscopic droplets. During the process, the system will have both macroscopic and microscopic regions meaning the model must be able to represent both and convert between them.

Here we present and validate an algorithm for converting the dispersed phase between Eulerian and Lagrangian representations. Macroscopic regions are converted to particles as the dispersed phase is broken up. Meanwhile, particles are converted to macroscopic regions as they coalesce. First, we apply the model to turbulent jet breakup, a well-characterized system, comparing against published data. Next, it is validated against static mixers and agitated tanks, comparing to experimental results. Finally, performance is analyzed, demonstrating the acceleration gained by using GPU hardware.