Experimental investigation of streaky structures in a relaminarizing boundary layer
- 1 January 2002
- journal article
- Published by Taylor & Francis in Journal of Turbulence
- Vol. 3, N18
Abstract
An experimental investigation of a boundary layer subjected to a relaminarization process is performed. The initially turbulent boundary layer develops on a plate mounted inside a two-dimensional convergent channel, and the results show that the mean velocity profiles of the boundary layer develop towards the self-similar laminar solution. Two-point correlation measurements, performed by means of two miniaturized single-wire hot-wire probes with variable relative spanwise separation, show the presence of elongated longitudinal structures. The absolute spanwise separation of these streaks decreases in the downstream direction. However, if the size is normalized with the displacement thickness of the boundary layer, the relative streak spacing shows a significant increase. Also, when scaled with the viscous length scale l* the streak spacing (defined as average distance between low- and high-speed streaks) increases from about 60l* in the turbulent boundary layer to 150-180l* in the relaminarizing region. T...Keywords
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