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The three-dimensional character of a nominally two-dimensional separated turbulent shear flow

Published online by Cambridge University Press:  26 April 2006

M. P. Jaroch  and
H.-H. Fernholz
M. P. Jaroch
Affiliation:
Hermann-Föttinger-Institut, Technische Universität Berlin, D-1000, Berlin 12, West Germany Present address: Audi AG, Ingolstadt, West Germany.
H.-H. Fernholz
Affiliation:
Hermann-Föttinger-Institut, Technische Universität Berlin, D-1000, Berlin 12, West Germany
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Abstract

Extensive experiments were performed in the highly turbulent shear layer and in the reverse-flow region downstream of a normal plate followed by a long splitter plate in its plane of symmetry. Whereas the earlier measurements of Ruderich & Fernholz (1986) and Castro & Haque (1987) concentrated on the plane of symmetry (x, y-plane, z = 0), the present investigation reveals the full extent of the three-dimensional behaviour of the flow by presenting data in the whole flow field. Spanwise measurements of five components of the Reynolds stress tensor, of integral timescales, and of mean and fluctuating values of the skin friction were carried out by the pulsed-wire technique. Integral lengthscales and spectra outside the reverse-flow region were measured using hot wires. In order to keep three-dimensional effects as small as possible, the aspect ratio was large (model width was 2.55 times the length of the reverse-flow region) and the blockage ratio and free-stream turbulence intensity were low. Despite these efforts the flow investigated here must be considered three-dimensional and classified as both pressure and shear driven. There appears to be a connection between the shape of the reverse-flow region and the level of the fluctuating velocities. Measurements of power spectral densities revealed no flapping motion of the separated turbulent shear layer.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 205 , August 1989 , pp. 523 - 552
Copyright
© 1989 Cambridge University Press

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References

Adams, E. W., Johnston, J. P. & Eaton, J. K. 1984 Experiments on the structure of a turbulent reattaching flow. Rep. MD-43. Stanford University, Stanford, CA.
Bradbury, L. J. S. & Castro, I. P. 1971 A pulsed wire technique for velocity measurements in highly turbulent flows. J. Fluid Mech. 49, 657–691.Google Scholar
Brederode, V. A. S. L. de 1975 Three-dimensional effects in nominally two-dimensional flows. Ph.D. Thesis, Imperial College of Science and Technology, University of London.
Castro, I. P. 1985 Time-domain measurements in separated flows. J. Fluid Mech. 150, 183–201.Google Scholar
Castro, I. P. & Cheun, B. S. 1982 The measurement of Reynolds stresses with a pulsed wire anemometer. J. Fluid Mech. 118, 45–58.Google Scholar
Castro, I. P. & Dianat, M. 1983 Surface flow patterns on rectangular bodies in thick boundary layers. J. Wind. Engng Ind. Aerodyn. 11, 107–119.Google Scholar
Castro, I. P. & Haque, A. 1987 The structure of a turbulent shear layer bounding a separated region. J. Fluid Mech. 179, 439–468.Google Scholar
Cherry, N. 1982 The effects of stream turbulence on a separated flow with reattachment. Ph.D. Thesis, Dept. of Aeronautics, Imperial College of Science and Technology, University of London.
Cherry, N. J., Hillier, R. & Latour, M. E. M. P. 1984 Unsteady measurements in a separated and reattaching flow. J. Fluid Mech. 144, 13–46.Google Scholar
Dengel, P., Fernholz, H. H. & Hess, M. 1987 Skin-friction measurements in two- and three-dimensional highly turbulent flows with separation. Proc. 1st European Turbulence Conf. (ed. J. Mathieu & G. Comte Bellot). Springer.
Eaton, J. K. & Johnston, J. P. 1981 A review of research on subsonic turbulent flow reattachment. AIAA J. 19, 1093–1100.Google Scholar
Fernholz, H. H. & Vagt, J. D. 1981 Turbulence measurements in an adverse-pressure-gradient three-dimensional turbulent boundary layer along a circular cylinder. J. Fluid Mech. 111, 233–270.Google Scholar
Froebel, E. & Vagt, J.-D. 1974 Ein automatisch abgleichendes Flüssigkeitsmanometer mit digitaler Anzeige. DFVLR FB 74–80.
Hancock, P. E. 1980 The effect of free-stream turbulence on turbulent boundary layers. Ph.D. Thesis, Imperial College of Science and Technology, University of London.
Hillier, R., Latour, M. E. M. P. & Cherry, N. J. 1983 Unsteady measurements in separated and reattaching flows. 4th Turbulent Shear Flow Conf., Karlsruhe. Springer.
Jaroch, M. 1985 Development and testing of pulsed wire probes for measuring fluctuating quantities in highly turbulent flows. Exp. Fluids 3, 315–322.Google Scholar
Jaroch, M. 1987a Eine kritische Betrachtung der Methode diskreter Wirbel als Modell für eine abgelöste Strömung mit geschlossener Ablöseblase auf der Basis experimenteller Erkenntnisse. Dissertation, Hermann-Föttinger-Institut für Thermo- und Fluiddynamik, Technische Universität Berlin.
Jaroch, M. 1987b Oil flow visualization experiments in the separated and reattaching flow past a normal flat plate with a long wake splitter plate. Z. Flugwiss. 11, 230–236.Google Scholar
Jaroch, M. & Dahm, A. 1987 A new pulsed-wire probe for measuring the Reynolds stresses in the plane containing the main shear direction of a turbulent flow. Internal Rep. IB 01/87. Hermann-Föttinger-Institut für Thermo- und Fluiddynamik, Technische Universität Berlin, Berlin.
Jaroch, M. & Graham, J. M. R. 1988 An evaluation of the discrete vortex method as a model for the flow past a flat plate normal to the flow with a long wake splitter plate. J. Méc. Theor. Appl. 7, 105–134.Google Scholar
Kiya, M. & Sasaki, K. 1983 Structure of a turbulent separation bubble. J. Fluid Mech. 137, 83–113.Google Scholar
Kiya, M. & Sasaki, K. 1985 Structure of large-scale vortices and unsteady reverse flow in the reattaching zone of a turbulent separation bubble. J. Fluid Mech. 154, 463–491.Google Scholar
Kiya, M., Sasaki, K. & Arie, M. 1982 Discrete-vortex simulation of a turbulent separation bubble. J. Fluid Mech. 120, 219–244.Google Scholar
Latour, M. E. M. P. 1983 The effect of geometry and stream turbulence on separated flows. Ph.D. Thesis, Imperial College of Science and Technology, University of London.
Nakamura, Y. & Ozono, S. 1987 The effects of turbulence on a separated and reattaching flow. J. Fluid Mech. 178, 477–490.Google Scholar
Ota, T. & Itasaka, M. 1976 A separated and reattached flow on a blunt flat plate. Trans. ASME I: J. Fluids Engng 98, 79–86.Google Scholar
Roshko, A. & Lau, J. C. 1965 Some observations on transition and reattachment of a free shear layer in incompressible flow. Proc. 1965 Heat Transfer and Fluid Mech. Inst.
Ruderich, R. 1985 Entwicklung des Nachlaufs einer senkrechten Platte längs einer zur Anströmung parallelen ebenen Wand. Dissertation, Hermann-Föttinger-Institut für Thermo-und Fluiddynamik Technische Universität Berlin, Berlin.
Ruderich, R. & Fernholz, H. H. 1986 An experimental investigation of a turbulent shear flow with separation, reverse flow, and reattachment. J. Fluid Mech. 163, 283–322 (referred to as RF).Google Scholar
Smits, A. J. 1982 Scaling parameters for a time averaged separation bubble. Trans. ASME I: J. Fluids Engng 104, 178–184.Google Scholar
Wagner, P.-M. 1986 Entwicklung eines verbesserten Pulsdrahtanemometers zur Erfassung von Geschwindigkeiten und Korrelationen in turbulenten Strömungen. Diplomarbeit, Herman-Föttinger-Institut für Thermo- und Fluiddynamik TU Berlin, Berlin.