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On the speed of progressive waves in gust-tunnels of the QMC-type

Published online by Cambridge University Press:  04 July 2016

M. S. Ishaq  and
L. Bernstein
M. S. Ishaq
Affiliation:
Department of Aeronautical Engineering, Queen Mary College, London
L. Bernstein
Affiliation:
Department of Aeronautical Engineering, Queen Mary College, London
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Summary

In the Queen Mary College gust-tunnels, unsteady flows are generated by oscillating flaps attached to the downstream upper and lower surfaces of the contraction nozzle of a semi-open test section, open-return, low-speed wind-tunnel. The flow perturbations produced on the mainstream of velocity U∞, are of the travelling-wave type, with wave-velocity Q. Attention is drawn to the contradictory early measurements of Q/U∞. New data are presented which show Q/U∞ apparently diminishing along the tunnel axis from a high value near the nozzle exit to an asymptotic value of about 0·6 far downstream. Using a digital phase meter especially developed for the purpose it is shown that the explanation for this behaviour lies in the two-dimensional nature of the wave process in the region of the flaps.

Type
Research Article
Information
The Aeronautical Journal , Volume 91 , Issue 907 , September 1987 , pp. 321 - 332
Copyright
Copyright © Royal Aeronautical Society 1987 

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References

1. Bernstein, L. and Ishao, M.S. The laminar boundary layer on a fiat plate in periodic sideslip. J Fl Mech, 1987.175, 511–535.Google Scholar
2. Browand, F. K. An experimental investigation of the instability of an incompressible separated shear layer. J Fl Mech, 1966. 26, 281–307.Google Scholar
3. Cousteix, J., Desopper, R. and Houdeville, A. Transition d'une couche limite soumise à une oscillation de l'ecoulement exterieur. ONERA TP 1977-55. Presented at AGARD Conference on Laminar-turbulent transition, Copenhagen, 1977.Google Scholar
4. Freymuth, P. On transition in a separated laminar boundary layer. J.Fl Mech, 1966. 26, 683–704.Google Scholar
5. Gilman, J. and Bennett, R. M. A wind tunnel technique for measuring frequency response functions for gust load analysis. Presented at an Aircraft Design & Technology meeting, Los Angeles, 1965.Google Scholar
6. Hirosue, K., Kitamura, K., Murakami, Y. and Shindo, S. Design and development of the gust wind tunnel at the National Aerospace Laboratory. NAL TR-335, 1973.Google Scholar
7. Horlock, J. H. An unsteady flow wind-tunnel. Cambridge Univ Report CUED/A Turbo/TR56, 1974.Google Scholar
8. Hunt, G. K., Roberts, D. R. and Walker, D. Measurements of transient pressures on a narrow delta wing due to an upward gust. CR624, 1961.Google Scholar
9. Ishaq, M. S. An investigation of some flows in an oscillatory flow wind-tunnel. MPhil. Thesis, Univ of London, 1984.Google Scholar
10. Karlsson, S. K. E. An unsteady turbulent boundary layer. J Fl Mech, 5, 622, 1959.Google Scholar
11. Kelly, R. E. On the stability of an inviscid shear layer which is periodic in space and time. J Fl Mech, 27, 657–689, 1967.Google Scholar
12. Lam, C. Y. Unsteady laminar and turbulent boundary layer computationusingadifferential-differencemethod. PhD Thesis, Univ of London, 1983.Google Scholar
13. Lighthill, M. J. The response of laminar skin-friction and heat-transfer to fluctuations in the stream velocity. Proc Roy Soc. 1954. A224, 1–23.Google Scholar
14. Obremski, H. J. and Fejer, A. A. Transition in oscillating boundary layer flows. J. Fl Mech, 29, 93, 1967.Google Scholar
15. Parker, A. G. On delta wings in unsteady flow. PhD Thesis, Univ of London, 1970.Google Scholar
16. Patel, M. H. On laminar boundary layers in oscillatory flow. Proc Roy Soc. 1975. A347, 99.Google Scholar
17. Patel, M. H. and Hancock, G. J. A gust tunnel facility. ARC R&M 3802, 1976.Google Scholar
18. Pericleous, K. A. An oscillatory turbulent boundary layer in an adverse pressure gradient. Phd Thesis, Univ of London, 1977 Google Scholar
19. Reid, C. F. and Wrestler, C. G. An investigation of a device to oscillate a wind-tunnel airstream. NASA TN D-739, 1961.Google Scholar
20. Sawyer, R. A. 0.7 m x 10 m low speed gust tunnel. Dept of Mech Eng, Univ of Salford, 1970.Google Scholar
21. Schetzer, J. D. Gust generation experiments. Univ of Michi gan Rep. Presented at an AGARD meeting. 1954 Google Scholar
22. Siderides, G. and Bernstein, L. The growth of turbulence in a periodic flow. QMC EP-1048, 1982.Google Scholar
23. Stokes, G. G. On the effect of the internal friction of fluids on the motion of pendulums. Trans Camb Phil Soc, 1851. 9, 8.Google Scholar
24. Whitehead, L. G., Wu, L. and Waters, M. H. L. Contracting ducts of finite length. Aero Quarterly, 1951. 2, 254–271.Google Scholar