Direct numerical simulation of vortex ring evolution from the laminar to the early turbulent regime


Archer, P.J., Thomas, T.G. and Coleman, G.N. (2008) Direct numerical simulation of vortex ring evolution from the laminar to the early turbulent regime Journal of Fluid Mechanics, 598, pp. 201-226. (doi:10.1017/S0022112007009883).

Download

[img] PDF direct_numerical_simulation_of_vortex_ring_evolution_from_the_laminar_to_the_early_turbulent_regime.pdf - Version of Record
Download (1MB)

Description/Abstract

Direct numerical simulation is used to study the temporal development of single vortex rings at various Reynolds numbers and core thicknesses. Qualitative differences between the evolution of thin- and thick-core rings are observed leading to a correction factor to the classical equation for the ring translational velocity. We compare the obtained linear modal growth rates with previous work, highlighting the role of the wake in triply periodic numerical simulations. The transition from a laminar to a turbulent ring is marked by the rearrangement of the outer core vorticity into a clearly defined secondary structure. The onset of the fully turbulent state is associated with shedding of the structure in a series of hairpin vortices. A Lagrangian particle analysis was performed to determine the ring entrainment and detrainment properties and to investigate the possibility of an axial flow being generated around the circumference of the core region prior to the onset of turbulence.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1017/S0022112007009883
ISSNs: 0022-1120 (print)
Keywords: vortex rings, direct numerical simulation
Subjects:

Organisations: Aerodynamics & Flight Mechanics
ePrint ID: 52010
Date :
Date Event
March 2008Published
Date Deposited: 02 Jun 2008
Last Modified: 16 Apr 2017 18:04
Further Information:Google Scholar
URI: http://eprints.soton.ac.uk/id/eprint/52010

Actions (login required)

View Item View Item