Search for large-scale coherent structures in the nearly self-preserving region of a turbulent axisymmetric jet

J. Tso, L. S.G. Kovasznay, A. K.M.F. Hussain

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

In an attempt to explore the existence of large-scale coherent structures in the nearly self-preserving region of an axisymmetric free air jet, a 2.54 cm air jet at a Reynolds number ReD = 6.8 × 104 has been investigated for x/D≥ 40 via both long and short time-averaged space-time correlation measurements. Conventional space-time correlation data with probe separations in the stream wise direction by as much as 25 diameters suggest the passage of large-scale organized structures. The radial extent of these structures is about one local jet diameter, and the azimuthal extent is about a quadrant of the cross-section. Recurring quasi-periodic patterns are observed in the time series of short time-averaged correlations between longitudinal velocity fluctuations obtained with two arrays of hot-wires separated in the streamwise direction. These orderly patterns provide direct evidence for the existence of these structures. Quantitative details of these structures are now being investigated.

Original languageEnglish
Pages (from-to)503-508
Number of pages6
JournalJournal of Fluids Engineering, Transactions of the ASME
Volume103
Issue number4
DOIs
StatePublished - Dec 1981

Fingerprint Dive into the research topics of 'Search for large-scale coherent structures in the nearly self-preserving region of a turbulent axisymmetric jet'. Together they form a unique fingerprint.

Cite this