Experimental Study of Drop Deformation and Breakup in a Model Multitoothed Rotor-Stator

Abstract

The objective of this work is to experimentally study the deformation behavior and breakup process suffered by a droplet submitted to the complex flow developed in a model multitoothed rotor-stator. The studied systems consist of an aqueous solution of polyvinylpyrrolidone in which droplets of diverse silicon oils are dispersed. Experiments are recorded with a digital camera, placed in vertical position, whose images are digitally analyzed. It is found that the drop deformation increases with increasing rotor rotational velocity, showing peaks of deformation corresponding to the proximity of the teeth. Drop breakup is achieved for all studied viscosity ratios. The breakup mechanism depends on the rotor-stator rotational dynamics, with breakup being more effective when the rotor teeth approach the stator teeth.