Correlation measurements and structure angles in a turbulent boundary layer recovering from convex curvature

Amy E. Alving, Alexander J. Smits

Research output: Contribution to journalConference article

1 Scopus citations

Abstract

Simultaneous, multiple point turbulence measurements were made in a boundary layer upstream and downstream of a 90° convex bend. Two-point space-time correlation coefficients Ruu(O,ξ,O,τ) were computed for several separation distances ξ. The time delay τmax corresponding to the maximum value of Ruu was used to define a structure angle θ, where θ = tan-1 [ξ/(Ucτmax)], and Uc is the best estimate for the convection velocity. For the undisturbed boundary layer, θ takes low values near the wall, increases to 30°-40° in the central portion of the layer, and increases further near the boundary layer edge. At the exit from the convex curvature, θ is largely unchanged. In the relaxing boundary layer θ appears to increase over most of the boundary layer thickness. The sensitivity of the structure angle to the probe separation distance, and the significance of the results in terms of large-scale organized motions are discussed. The instantaneous structure angle can be defined in terms of short-time correlations, and some of the difficulties associated with this concept are also discussed.

Original languageEnglish (US)
Pages (from-to)507-528
Number of pages22
JournalProceedings of the International Centre for Heat and Mass Transfer
StatePublished - Dec 1 1988
EventNear-Wall Turbulence: 1988 Zoran Zaric Memorial Conference - Dubrovnik, Ygosl
Duration: May 16 1988May 20 1988

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Fingerprint Dive into the research topics of 'Correlation measurements and structure angles in a turbulent boundary layer recovering from convex curvature'. Together they form a unique fingerprint.

  • Cite this