Three-dimensionality of organized structures in a plane turbulent wake

Michio Hayakawa, Fazle Hussain

Research output: Contribution to journalArticle

88 Scopus citations

Abstract

This paper describes a quantitative study of the three-dimensional nature of organized motions in a turbulent plane wake. Coherent structures are detected from the instantaneous, spatially phase-correlated vorticity field using certain criteria based on size, strength and geometry of vortical structures. With several combinations of X-wire rakes, vorticity distributions in the spanwise and transverse planes are measured in the intermediate region (10d x 40d) of the plane turbulent wake of a circular cylinder at a Reynolds number of 13000 based on the cylinder diameter d. Spatial correlations of smoothed vorticity signals as well as phase-aligned ensemble-averaged vorticity maps over structure cross-sections yield a quantitative measure of the spatial coherence and geometry of organized structures in the fully turbulent field. The data demonstrate that the organized structures in the nominally two-dimensional wake exhibit significant three-dimensionality even in the near field. Using instantaneous velocity and vorticity maps as well as correlations of vorticity distributions in different planes, some topological features of the dominant coherent structures in a plane wake are inferred.

Original languageEnglish
Pages (from-to)375-404
Number of pages30
JournalJournal of Fluid Mechanics
Volume206
DOIs
StatePublished - Sep 1989

Fingerprint Dive into the research topics of 'Three-dimensionality of organized structures in a plane turbulent wake'. Together they form a unique fingerprint.

  • Cite this