A Numerical Method and Study of Viscoelastic Droplet Breakup

Abstract This paper presents a comprehensive study of viscoelastic, droplet-breakup physics using multiphase computational fluids dynamics (CFD) based on the volume of fluid (VOF) method. The specific challenge and novelty are the overall outcome and methods used to explore viscoelastic breakup physics. In the context of VOF, the method approximates both viscous and elastic characteristics of the saliva with a function based on the Carreau-Yasuda (CY) model. The CY model is traditionally used for modeling blood flow and here is extended to approximate saliva. The foundation of the model couples the shear rate to drive both a variable viscosity and relaxation time. The results indicate a strong stabilizing effect of viscoelastic fluids that indicates that conventional breakup models provide a conservative estimate of droplet size as is relevant to the transmission pathogens.