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Characteristics of ejections in turbulent channel flow

Published online by Cambridge University Press:  21 April 2006

D. G. Bogard  and
W. G. Tiederman
D. G. Bogard
Affiliation:
School of Mechanical Engineering, Purdue University, W. Lafayette, IN 47907 USA Present address: Mechanical Engineering Department, University of Texas, Austin, TX 78712, USA
W. G. Tiederman
Affiliation:
School of Mechanical Engineering, Purdue University, W. Lafayette, IN 47907 USA
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Abstract

Quantitative measurements of the structure of ejections from the wall region have been made using conditional-sampling techniques. Discrete ejections from a burst event were identified using fluorescent-dye flow visualization simultaneously with streamwise, u, and normal, v, velocity measurements. These velocity measurements, at y+ = 15, were conditionally sampled based on different phases of the ejection event. Features of the ejection which were educed from the conditional sampling were found to be very sensitive to the phase alignment. Results showed that ejections were characterized by a rapid deceleration at the leading edge followed by a strong positive velocity gradient at the trailing edge. An intense second-quadrant uv spike occurred immediately following the leading edge. This uv peak was highly correlated with a positive peak in the v velocity. The first ejection which occurred in a burst was found to be significantly more intense than the following ejections. Many characteristics of bursts which have been obtained from previous conditional-sampling studies were found to correspond to different phases of the ejection event.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 179 , June 1987 , pp. 1 - 19
Copyright
© 1987 Cambridge University Press

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References

Alfredsson, P. H. & Johansson, A. Y. 1984 On the detection of turbulence-generating events. J. Fluid Mech. 139, 325.Google Scholar
Blackwelder, R. F. 1977 On the role of phase information in conditional sampling. Phys. Fluids 20, S232.Google Scholar
Blackwelder, R. F. & Haritonidis, J. H. 1983 Scaling on the bursting frequency in turbulent boundary layers. J. Fluid Mech. 132, 87.Google Scholar
Blackwelder, R. F. & Kaplan, R. E. 1976 On the bursting phenomenon near the wall in bounded turbulent shear flows. J. Fluid Mech. 76, 89.Google Scholar
Bogard, D. G. 1982 Investigation of burst structures in turbulent channel flows through simultaneous flow visualization and velocity measurements. Ph.D. thesis, Purdue University.
Bogard, D. G. & Tiederman, W. G. 1983 Investigation of flow visualization techniques for detecting turbulent bursts. Symposium on Turbulence 1981, p. 289 University of Missouri-Rolla.
Bogard, D. G. & Tiederman, W. G. 1986 Burst detection with single point velocity measurements. J. Fluid Mech. 162, 389.Google Scholar
Chen, C. P. & Blackwelder, R. F. 1978 The large-scale motion in a turbulent boundary layer; a study using temperature contamination. J. Fluid Mech. 89, 1.Google Scholar
Comte-Bellot, G., Sabot, J. & Saleh, I. 1978 Detection of intermittent events maintaining Reynolds stress. In Proc. Dynamic Flow Conf.-Dynamic Measurements in Unsteady Flows, p. 213. Marseille, Baltimore, Skovlunde, Denmark.
Corino, E. R. & Brodkey, R. S. 1969 A visual study of turbulent shear flow. J. Fluid Mech. 37, 1.Google Scholar
Johansson, A. Y. & Alfredsson, P. H. 1982 On the structure of turbulent channel flow. J. Fluid Mech. 122, 295.Google Scholar
Kim, H. T., Kline, S. J. & Reynolds, W. C. 1971 The production of turbulence near a smooth wall in a turbulent boundary layer. J. Fluid Mech. 50, 133.Google Scholar
Offen, G. R. & Kline, S. J. 1975 A comparison and analysis of detection methods for the measurement of production in a boundary layer. In Proc. 3rd Biennial Symposium of Turbulence in Liquids, p. 289, University of Missouri-Rolla.
Rajagopalan, S. & Antonia, R. A. 1984 Conditional averages associated with the fine structure in a turbulent boundary layer. Phys. Fluids 27, 1966.Google Scholar
Subramanian, C. S., Rajagopalan, S., Antonia, R. A. & Chambers, A. J. 1982 Comparison of conditional sampling and averaging techniques in a turbulent boundary layer. J. Fluid Mech. 123, 335.Google Scholar
Yule, A. J. 1979 Phase scrambling effects and turbulence data analysis. 2nd Symp. on Turbulent Shear Flow, p. 7–1. Imperial College, London.
Wallace, J. M., Brodkey, R. S. & Eckelmann, H. 1977 Pattern-recognized structures in bounded turbulent shear flows. J. Fluid Mech. 142, 121.Google Scholar