Break-up and droplet formation in shear thinning compound liquid jets

The break-up of a compound liquid jet into droplets has relevance to many practical situations in engineering and science. In this paper, we investigate the dynamics associated with the break-up of a non-Newtonian shear thinning compound liquid jet obeying the Carreau model. A long wavelength asymptotic expansion is used to reduce the governing equations of the problem into a set of 1D partial differential equations, which describe the evolution of the leading order axial velocity of the jet as well as the radii of both the inner and the outer interfaces. We solve these equations using a numerical method, based on finite differences, to investigate the effect of changing key parameters on break-up dynamics and droplet sizes.