A computational study of the break-up of a complex liquid ligament in a turbulent crossflow

The use of complex liquids in industrial spray processes is wide ranging and is a crucial component in areas such as food and pharmaceutical manufacturing. In these processes, the complex liquid is subjected to turbulent flow conditions causing the fluid to undergo rapid shearing and deformation causing the fluid to continually breakdown into sheets, ligaments, and droplets. While the process of atomization itself is quite complex, the use of complex fluids results in an additional layer of complexity because of the polymers and particulates that give these fluids an inherent microstructure. This microstructure gives rise to complex behavior such as high effective viscosity, shear-thinning and viscoelasticity not found in Newtonian fluids and ultimately alters the atomization behavior of the liquid. Because the process of atomization is highly multi-scale, this work simplifies the flow configuration to look at a single isolated liquid ligament in a turbulent crossflow to examine how this intrinsic complex behavior impacts the fundamental physics - Rayleigh-Plateau and Rayleigh-Taylor instabilities - that drive atomization. This study uses the volume-of-fluid method to transport the liquid-gas interface. It will begin by looking at the impact of high viscosity on break-up and then incorporate shear-thinning using the Carreau fluid model and FENE style viscoelastic models to include elastic stresses in the governing equations.