Skip to main content
×
Home
    • Aa
    • Aa

Large-scale motions in a supersonic turbulent boundary layer

  • B. GANAPATHISUBRAMANI (a1), N. T. CLEMENS (a1) and D. S. DOLLING (a1)
Abstract

Wide-field particle image velocimetry measurements were performed in a Mach 2 turbulent boundary layer to study the characteristics of large-scale coherence at two wall-normal locations ($y/\delta\,{=}\,0.16$ and 0.45). Instantaneous velocity fields at both locations indicate the presence of elongated streamwise strips of uniform low- and high-speed fluid (length$\,{>}\,8\delta$). These long coherent structures exhibit strong similarities to those that have been found in incompressible boundary layers, which suggests an underlying similarity between the incompressible and supersonic regimes. Two-point correlations of streamwise velocity fluctuations show coherence over a longer streamwise distance at $y/\delta\,{=}\,0.45$ than at $y/\delta\,{=}\,0.16$, which indicates an increasing trend in the streamwise length scale with wall-normal location. The spanwise scale of these uniform-velocity strips increases with increasing wall-normal distance as found in subsonic boundary layers. The large-scale coherence observed is consistent with the very large-scale motion (VLSM) model proposed by Kim & Adrian (Phys. Fluids, vol. 11, 1999, p. 417) for incompressible boundary layers.

Copyright
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Fluid Mechanics
  • ISSN: 0022-1120
  • EISSN: 1469-7645
  • URL: /core/journals/journal-of-fluid-mechanics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×
MathJax

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 124 *
Loading metrics...

Abstract views

Total abstract views: 187 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 22nd October 2017. This data will be updated every 24 hours.