A Simplified Droplet Breakage Model to Simulate Continuous Emulsification by Hydrodynamic Cavitation

Liquid-liquid emulsions are central to numerous industries, including healthcare, food and nutrition, personal care, agrochemicals, and home care. Hydrodynamic cavitation offers an attractive platform for continuous emulsification. Computational models capable of predicting droplet size distributions (DSD) or at least the Sauter mean diameter (<i>d</i> ₃₂) of emulsions are essential for the appropriate design and operation of cavitation-induced emulsification. Full CFD (computational fluid dynamics) and PBM (population balance models) simulations for predicting DSD remain limited by their complexity and computational cost, as well as uncertainty in obtaining relevant model parameters. In this work, we reformulate our previously presented simplified drop breakage model to make it suitable for simulating continuous emulsification. The reformulated model was applied to dense oil-in-water emulsions produced using a vortex-based hydrodynamic cavitation device (VD) under varying operating conditions and oil volume fractions and different liquid-liquid systems. The previously published data of liquid-liquid emulsions using a hydrodynamic cavitation-based fluidic device was used to evaluate the model. The simplified droplet breakage model was evaluated for droplet sizes ranging from ∼1 to 100 μm, under pressure drops of 50-250 kPa and oil volume fractions of 0.05-0.45. For both liquid-liquid systems, the root-mean-square error varies between 0.002 and 0.6 μm. The simplified droplet breakage model presented here successfully captured the influence of process parameters (pressure drop and initial oil volume fraction) while maintaining ease of implementation and low computational costs. This approach provides a generalized and practical framework for simulating continuous emulsification, supporting the design and scale-up of next-generation emulsion systems.