Stability of a compressible axisymmetric swirling jet

Temporal linear stability of a compressible swirling axisymmetric jet is considered. It is found that with the addition of a modest amount of swirl, instability growth rates are substantially increased. Additionally, rotating jets are found to be highly unstable for disturbances with high azimuthal wave numbers. Such disturbances are absent for the case of nonswirling jets. Most importantly, it is found that the stabilizing influence of increasing Mach number is diminished with the introduction of swirl to the jet flow.