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Longitudinal vortices imbedded in turbulent boundary layers Part 2. Vortex pair with ‘common flow’ upwards

Published online by Cambridge University Press:  21 April 2006

R. D. Mehta
Affiliation:
Department of Aeronautics and Astronautics, JIAA, Stanford University, Stanford, CA 94305, USA
P. Bradshaw
Affiliation:
Department of Aeronautics, Imperial College, London SW7 2BY, UK

Abstract

Detailed mean flow and turbulence measurements have been made in a low-speed turbulent boundary layer in zero pressure gradient with an isolated, artificially generated vortex pair imbedded in it. The vortices, generated by two half-delta wings on the floor of the wind-tunnel settling chamber, rotate in opposite directions such that the ‘common flow’ between the vortices is away from the surface, and the vortex pair draws boundary-layer fluid upwards. The distance of the vortex cores above the surface grows downstream, and is roughly twice the local boundary-layer thickness. The cancellation of circulation by mixing of fluid from the two vortices is slow, and the vortices are identifiable down the full length of the test section. As in the case of the single vortex investigated in Part 1 of this series, large changes in structural parameters of the turbulence occur.

Type
Research Article
Copyright
© 1988 Cambridge University Press

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References

Bansod, P. & Bradshaw, P. 1972 The flow in S-shaped ducts. Aero. Q. 23, 131.Google Scholar
Bradshaw, P. & Cutler, A. D. 1987 Three-dimensional flows with imbedded longitudinal vortices. In Perspectives in Turbulent Studies (ed. H. U. Meier & P. Bradshaw), p. 382. Springer.
Eibeck, P. A. & Eaton, J. K. 1987 Heat transfer effects of a longitudinal vortex embedded in a turbulent boundary layer. Trans. ASME C: J. Heat Transfer 109, 16.Google Scholar
Gessner, F. B., Ferguson, S. D. & Lo, C. H. 1986 Experiments on supersonic turbulent flow development in a square duct. AIAA-86-1038.Google Scholar
Hoffmann, P. H., Muck, K. C. & Bradshaw, P. 1985 The effect of concave surface curvature on turbulent boundary layers. J. Fluid Mech. 161, 371.Google Scholar
Humphrey, J. A. C., Whitelaw, J. H. & Yee, G. 1981 Turbulent flow in a square duct with strong curvature. J. Fluid Mech. 103, 443.Google Scholar
Liandrat, J., Aupoix, B. & Cousteix, J. 1987 Calculation of longitudinal vortices imbedded in a turbulent boundary layer. In Turbulent Shear Flows 5 (ed. F. Durst et al.), p. 253. Springer.
Mokhtari, S. & Bradshaw, P. 1983 Longitudinal vortices in wind tunnel wall boundary layers. Aero J. 87, 233.Google Scholar
Morton, B. R. 1984 The generation and decay of vorticity. Geophys. Astrophys. Fluid Dyn. 28, 277.Google Scholar
Moser, R. D. & Moin, P. 1987 The effects of curvature in wall-bounded turbulent flows. J. Fluid Mech. 75, 479.Google Scholar
Patel, V. C. & Baek, J. H. 1987 Boundary layers in planes of symmetry. Part 1. Experiments in turbulent flow. AIAA J. 25, 550.Google Scholar
Pauley, W. C. & Eaton, J. K. 1987 An experimental study of the development of longitudinal vortex pairs embedded in a turbulent boundary layer. AIAA-87-1309.Google Scholar
Rogallo, R. S. & Moin, P. 1984 Numerical simulation of turbulent flows. Ann. Rev. Fluid Mech. 16, 99.Google Scholar
Shabaka, M. M. A., Mehta, R. D. & Bradshaw, P. 1985 Longitudinal vortices imbedded in turbulent boundary layers. Part 1. Single vortex. J. Fluid Mech. 155, 37.Google Scholar
Taylor, A. M. K. P. Whitelaw, J. H. & Yianneskis, M. 1984 Developing flow in S-shaped ducts II. Circular cross-section ducts. NASA CR 3759.Google Scholar
Westphal, R. V., Eaton, J. K. & Pauley, W. R. 1987 Interaction between a vortex and a turbulent boundary layer in a streamwise pressure gradient. In Turbulent Shear Flows 5 (ed. F. Durst et al.), p. 266. Springer.
Westphal, R. V. & Mehta, R. D. 1987 Interaction of an oscillating vortex with a turbulent boundary layer. AIAA-87-1246.Google Scholar