On the steady‐state drop size distribution in stirred vessels. Part II: Effect of continuous phase viscosity

Abstract

In Part I we used silicon oils with viscosities across six orders of magnitude to investigated the effect of the dispersed phase viscosity on the DSD of dilute emulsions. In this study we extended Part I by using three glucose aqueous solutions to thicken the continuous phases approximately an order of magnitude while keeping the Power number constant. It was found that increasing the continuous phase viscosity decreases the maximum drop size despite having drops well above the Kolmogorov length-scale. Our results are in disagreement with the mechanistic models for the turbulent inertia regime. The results were explained using the full turbulent energy spectrum proposed by Pope 2 instead of the Kolmogorov -5/3 spectrum. Our analysis revealed that most of the steady-state drop sizes do not fall in the isotropic turbulence size range.