Evolution of isolated turbulent trailing vortices

Duraisamy, K. and Lele, S. (2008) Evolution of isolated turbulent trailing vortices. Physics of Fluids, 20(3), 035102-035102. (doi: 10.1063/1.2840200)

Abstract

In this work, the temporal evolution of a low swirl-number turbulent Batchelor vortex is studied using pseudospectral direct numerical simulations. The solution of the governing equations in the vorticity-velocity form allows for accurate application of boundary conditions. The physics of the evolution is investigated with an emphasis on the mechanisms that influence the transport of axial and angular momentum. Excitation of normal mode instabilities gives rise to coherent large scale helical structures inside the vortical core. The radial growth of these helical structures and the action of axial shear and differential rotation results in the creation of a polarized vortex layer. This vortex layer evolves into a series of hairpin-shaped structures that subsequently breakdown into elongated fine scale vortices. Ultimately, the radially outward propagation of these structures results in the relaxation of the flow towards a stable high-swirl configuration. Two conserved quantities, based on the deviation from the laminar solution, are derived and these prove to be useful in characterizing the polarized vortex layer and enhancing the understanding of the transport process. The generation and evolution of the Reynolds stresses is also addressed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Duraisamy, Mr Karthikeyan
• Authors: Duraisamy, K., and Lele, S.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Research Group: Rotorcraft Aeromechanics
• Journal Name: Physics of Fluids
• Journal Abbr.: Phys. fluids
• Publisher: American Institute of Physics
• ISSN: 1070-6631
• ISSN (Online): 1089-7666
• Published Online: 03 March 2008
• Copyright Holders: Copyright © 2008 American Institute of Physics
• First Published: First published in Physics of Fluids 20(3):035102-035102-11
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.