Stability criteria of an immersed annulus swirling jet in a zero gravity environment

The present work deals with the stability properties of an immersed annulus swirling jet in a zero gravity environment. The considered system is composed of two streaming coaxial fluid cylinders, embedded in a third streaming fluid, where the intermediate one (annulus) has a uniform swirl speed. The fluids are immiscible, inviscid, and incompressible. The linear stability criteria of the model are discussed analytically and stability diagrams are obtained. We conclude that the radii ratio, the Weber number and the swirl number play a significant role in determining the dynamics of the developing interfacial patterns.