Absolute instability of power law liquid jets

Non-Newtonian fluid threads are common in many natural and synthetic processes. An appreciation of how such threads break into droplets has been a subject of study for a long time. In this paper we investigate the absolute instability of a cylindrical thread, modelled as a power law fluid, falling under gravity surrounded by an inviscid medium. Particular attention is paid to investigating the effects of the gas-to-liquid density ratio and the Reynolds number as well as the influence of the flow index number on critical Weber numbers (which mark the transition between convective and absolute instability). Our results determine the convective to absolute instability boundary (CAIB) for a number of different parameter values.