Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-09T06:29:48.076Z Has data issue: false hasContentIssue false

Low-dimensional dynamics of a turbulent wall flow

Published online by Cambridge University Press:  22 June 2001

JAVIER JIMÉNEZ
Affiliation:
School of Aeronautics, U. Politécnica, 28040 Madrid, Spain Centre for Turbulence Research, Stanford U., Stanford, CA 94305, USA
MARK P. SIMENS
Affiliation:
School of Aeronautics, U. Politécnica, 28040 Madrid, Spain

Abstract

The low-dimensional dynamics of the structures in a turbulent wall flow are studied by means of numerical simulations. These are made both ‘minimal’, in the sense that they contain a single copy of each relevant structure, and ‘autonomous’ in the sense that there is no outer turbulent flow with which they can interact. The interaction is prevented by a numerical mask that damps the flow above a given wall distance, and the flow behaviour is studied as a function of the mask height. The simplest case found is a streamwise wave that propagates without change. It takes the form of a single wavy low-velocity streak flanked by two counter-rotating staggered quasi-streamwise vortices, and is found when the height of the numerical masking function is less than δ+1 ≈ 50. As the mask height is increased, this solution bifurcates into an almost-perfect limit cycle, a two-frequency torus, weak chaos, and full-edged bursting turbulence. The transition is essentially complete when δ+1 ≈ 70, even if the wall-parallel dimensions of the computational box are small enough for bursting turbulence to be metastable, lasting only for a few bursting cycles. Similar low-dimensional dynamics are found in somewhat larger boxes, containing two copies of the basic structures, in which the bursting turbulence is self-sustaining.

Type
Research Article
Copyright
© 2001 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.)