INSTABILITIES AND LARGE STRUCTURES IN REATTACHING BOUNDARY LAYERS
The underlying premise in this work is that large structures in turbulent shear flows are not universal and similar large structures in different flows owe their origins to basically similar instabilities. The turbulent boundary-layer flow over a backward-facing step and also the re-attaching transitional boundary layer behind a large spanwise rod have been studied experimentally in parallel primarily to understand the origin of the curious large structures observed in the far downstream region (after 39 set heights) of the former flowfield. Simultaneous flow visualisation and hot-wire anemometry and also plain-flow visualisation have been carried out. In the backward facing step, the three-dimensional mixing layer developing after detachment persists even after re-attachment. The flow does not recover fully back to a regular turbulent boundary layer even far downstream of re-attachment. The turbulence-producing instability of a turbulent boundary layer continues to compete with the wall-bounded mixing layer instability, giving rise to the curious schismatic arrays of large structures.
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Supplemental Notes:
- AIAA J, v 29, n 7, July 1991, p 1149 [7 p, 25 ref, 15 fig]
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Authors:
- Bandyopadhyay, P R
- Publication Date: 1991
Language
- English
Subject/Index Terms
- TRT Terms: Boundary layer; Flow; Mechanical stability; Shear rate; Turbulence
- Candidate Terms: Turbulent flow
- Uncontrolled Terms: Shear flow
- Subject Areas: Marine Transportation;
Filing Info
- Accession Number: 00701073
- Record Type: Publication
- Source Agency: British Maritime Technology
- Files: TRIS
- Created Date: Aug 14 1995 12:00AM