Linear stability of Landau jet: non-parallel effects

Abstract

Abstract We perform linear stability analysis of Landau jet using quasi-parallel approximation and self-similar approach. While the former detects only sinusoidal unstable modes, the latter also captures axisymmetric disturbances in agreement with previous results. The direct comparison of dispersion curves and eigenmode shapes for m = 1 and ReD ≈ 56 indicates that low frequencies are poorly described within quasi-parallel approximation making this approach questionable for a laminar-turbulent transition model.