Hostname: page-component-745bb68f8f-d8cs5 Total loading time: 0 Render date: 2025-01-11T22:42:38.849Z Has data issue: false hasContentIssue false
  • English
  • Français

The interaction of the piston vortex with a piston-generated vortex ring

Published online by Cambridge University Press:  27 January 2004

JOHN E. CATER ,
JULIO SORIA  and
T. T. LIM
JOHN E. CATER
Affiliation:
Laboratory for Turbulence Research in Aerospace & Combustion, Department of Mechanical Engineering, Monash University, P.O. Box 31, Melbourne, Victoria 3800, Australia
JULIO SORIA
Affiliation:
Laboratory for Turbulence Research in Aerospace & Combustion, Department of Mechanical Engineering, Monash University, P.O. Box 31, Melbourne, Victoria 3800, Australia
T. T. LIM
Affiliation:
Mechanical Engineering Department, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
Get access Rights & Permissions [Opens in a new window]

Abstract

This paper presents the results of an experimental investigation of the effects of a piston vortex on the vorticity evolution of a vortex ring. The rings are produced by the roll-up of a shear layer at a circular orifice in a plane wall and have a Reynolds number of 2000 based on the ejection velocity and orifice diameter. The generation mechanism is a piston moving inside a cylinder with a stroke length of two piston diameters. The experimental apparatus is similar to that used by Glezer & Coles (1990) where the piston finishes flush with the orifice, with the result that a piston vortex produced by the apparatus interacts with the vortex ring. Instantaneous velocity field measurements using cross-correlation digital particle image velocimetry reveal that the piston vortex not only increases the circulation of the ring but also creates an asymmetric vorticity distribution of the vortex core. It is found that ‘imperfect’ merging of the piston vortex with the primary vortex ring promotes the growth of an instability which leads to early transition to turbulence of initially laminar vortex rings.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 499 , 25 January 2004 , pp. 327 - 343
Copyright
© 2004 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)