Journal ArticleDOI
Near-neutral centre-modes as inviscid perturbations to a trailing line vortex
Keith Stewartson,S. N. Brown +1 more
TLDR
In this article, a columnar trailing line vortex is found to have near-neutral center modes, occurring at moderate values of the azimuthal wavenumber n, which are the analogue of the ring modes for large n discussed by Stewartson & Capell (1985).Abstract:
Inviscid linear perturbations to a columnar trailing line vortex are found in the form of centre-modes. These near-neutral modes, occurring at moderate values of the azimuthal wavenumber n , are the analogue of the ring modes for large n discussed by Stewartson & Capell (1985). The appearance and disappearance of these modes as the swirl parameter varies may partly explain the difficulties encountered by numerical analysts in the computation of such modes. In addition, instabilities are found at higher values of the swirl parameter than have previously been reported.read more
Citations
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Journal ArticleDOI
On the viscous modes of instability of a trailing line vortex
TL;DR: In this paper, a viscous linear stability analysis of a trailing line (Batchelor) vortex is presented, employing a staggered Chebyshev spectral collocation technique, very accurate results were obtained.
Journal ArticleDOI
Viscous instabilities in trailing vortices at large swirl numbers
David Fabre,Laurent Jacquin +1 more
TL;DR: In this article, a family of viscous instabilities existing in a range of parameters which are usually assumed to be stable, namely large swirl parameters (q > 1.5) and large Reynolds numbers, are studied numerically using an original and highly accurate Chebyshev collocation method.
Journal ArticleDOI
Inviscid instability of the Batchelor vortex: Absolute-convective transition and spatial branches
TL;DR: In this article, the spatio-temporal instability properties of the Batchelor q-vortex, as a function of swirl ratio q and external axial flow parameter a, were examined.
Journal ArticleDOI
Transient growth in vortices with axial flow
C. J. Heaton,Nigel Peake +1 more
TL;DR: In this paper, the authors investigated transient growth in high-Reynolds-number vortices with axial flow and found that strong transient effects are present in the moderate to high-swirl regime of practical interest.
Journal ArticleDOI
Viscous effects in the absolute-convective instability of the Batchelor vortex
Cornel Olendraru,Antoine Sellier +1 more
TL;DR: In this paper, the effects of viscosity on the instability properties of the Batchelor vortex were investigated in the convectively unstable regime for different values of the swirl parameter q and the co-flow parameter a at several Reynolds numbers Re.
References
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Journal ArticleDOI
On the hydrodynamic and hydromagnetic stability of swirling flows
Louis N. Howard,A. S. Gupta +1 more
TL;DR: In this paper, some general stability criteria for non-dissipative swirling flows are derived, and extended to the case of an electrically conducting fluid in the presence of axial magnetic field and current.
Journal ArticleDOI
A sufficient condition for the instability of columnar vortices
TL;DR: In this paper, the inviscid instability of columnar vortex flows in unbounded domains to three-dimensional perturbations is considered and a sufficient condition for columnar vortices is formulated.
Journal ArticleDOI
The stability of a trailing line vortex. Part 1. Inviscid theory
TL;DR: The inviscid stability of swirling flows with mean velocity profiles similar to that obtained by Batchelor (1964) for a trailing vortex from an aircraft is studied with respect to infinitesimal non-axisymmetric disturbances as discussed by the authors.
Journal ArticleDOI
The inviscid stability of a trailing line vortex
Peter W. Duck,M. R. Foster +1 more
TL;DR: A finite difference method has been developed to study the inviscid stability of swirling flows to small non-axisymmetric disturbances as mentioned in this paper, which appears to be more efficient and simpler to implement for this class of problem, than previously reported methods.
Journal ArticleDOI
On the instability of rapidly rotating shear flows to non-axisymmetric disturbances
TL;DR: In this article, the stability of Poiseuille flow in a rotating pipe was investigated and the growth rate of the most rapidly growing disturbance was found to be 2eΩ.