Author(s)

K.P. Judd, Z. Rusak & A. Hirsa

Abstract

Analytical and experimental methods are used to study the presence of vortex break- down states appearing on slender vortices in slightly diverging streamtubes. Asymp- totic methods are used to obtain analytical solutions of the steady and axisymmet- ric Euler equations for near-critical rotating flows. Multiple flow states which de- scribe either a small perturbation of the base rotating flow or a larger-amplitude disturbance may appear. The stability of the various flow states around the critical swirl is also studied. It is found that, for swirling flows below the critical value, the slightly perturbed states are linearly stable whereas the large-disturbance states are unstable to a certain mode of

Keywords