Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-12-03T19:15:38.291Z Has data issue: false hasContentIssue false
  • English
  • Français

Flow visualisation of the helicopter brown-out phenomenon

Part of: 75 year anniversary of Aeronautical Engineering at Glasgow University

Published online by Cambridge University Press:  03 February 2016

N. D. Nathan  and
R. B. Green
N. D. Nathan
Affiliation:
Department of Aerospace Engineering, University of Glasgow, Glasgow, Scotland, UK
R. B. Green
Affiliation:
[email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Quantitative and qualitative results of a series of experiments conducted on a rotor in ground effect at low forward speeds are presented. The velocity over a wide area of the ground effect wake was measured using particle image velocimetry, and the evolution of the flow is described as the forward speed increases. The formation of a dust cloud leading to so-called helicopter brown-out was simulated through a series of flow visualisation experiments. The technique involved sprinkling a fine dust on the ground below and ahead of the rotor. Larger dust clouds were observed at lower forward speed, and the dust cloud penetrated into the areas of the flow including those where vorticity levels were of low magnitude and occasional velocity fluctuations from the mean were large.

Type
Research Article
Information
The Aeronautical Journal , Volume 113 , Issue 1145 , July 2009 , pp. 467 - 478
Copyright
Copyright © Royal Aeronautical Society 2009 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

2. Zbrozek, J., Ground effect on the lifting rotor, British ARC, R & M No 2347, July 1947.Google Scholar
2. Fradenburgh, E.A., The helicopter and the groundeffect machine. J American Helicopter Society, October 1960, 5, (4), p 24.Google Scholar
3. Curtiss, H.C., Sun, M., Putman, W.F. and Hanker, E.J., Rotor aerodynamics in ground effect atlow advance ratios, J American Helicopter Society, 1984, 29, (1), pp 48–55.Google Scholar
4. Leishman, J.G., Principles of Helicopter Aerodynamics, 2nd Ed Cambridge Aerospace Series. Cambridge University Press, Cambridge, UK, 2006.Google Scholar
5. Curtiss, H.C., Erdman, W. and Sun, M., Ground effect aerodynamics, Vertica, 1987, 11, (1-2), pp 29–42.Google Scholar
6. Hayden, J.S., The effect of the ground on helicopter hovering power required. 32nd Annual Forum of the American Helicopter Society, May 1976.Google Scholar
7. Brown, R.E. and Whitehouse, G.R., Modelling rotorwakes in ground effect, J American Helicopter Society, 2004, 49, (3), pp 238–249.Google Scholar
8. Sheridan, P.F. and Wiesner, W., Aerodynamics of helicopter flight near the ground. In 33rd Annual Forum of the American Helicopter Society, May 1977.Google Scholar
9. Ganesh, B.A. and Komerath, N., Unsteady aerodynamics of rotorcraft in ground effect. In 22nd Applied Aerodynamics Conference and Exhibit, Providence, Rhode Island, USA, 16-19 August 2004.Google Scholar
10. Saijo, T., Ganesh, B., Huang, A. and Komerath, N., Development of unsteadiness in a rotor wake in ground effect, In 21st AIAA Applied Aerodynamics Conference, Orlando, Florida, USA, June 2003.Google Scholar
11. Pulla, D. and Conlisk, A., The long term structure of a rotor wake in ground effect. In 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, USA, January 2005.Google Scholar
12. Ganesh, B.A., Komerath, N., Pulla, D. and Conlisk, A., Unsteady aerodynamics of rotorcraft in ground effect. In 43rd Aerospace Sciences Meeting and Exhibit, Reno, Nevada, USA, January 2005.Google Scholar
13. Boyd, E.A. and Kusmarwanto, I., Ground effect on a rotor wake. In Cranfield Institue of Technology, College of Aeronautics, Cranfield, UK, Report 8323, 1983.Google Scholar
14. Kusmarwanto, I., Ground Effect on a Rotor Wake, PhD thesis, Cranfield Institute of Technology, College of Aeronautics, Cranfield, UK, March 1985.Google Scholar
15. Ganesh, B.A. and Komerath, N., Study of groundvortex structure of rotorcraft in ground effect atlow advance ratios. In 24th Applied Aerodynamics Conference, San Francisco, California, USA, 5-8 June 2006.Google Scholar
16. Chen, A.L., Jacob, J.D. and Savas, Ö. Dynamics of corotating vortex pairs in the wakes of flapped airfoils, J Mechanics, 1999, (382), pp 155–193.Google Scholar
17. Ramasamy, M. and Leishman, J.G., Benchmarking piv with ldv for rotor wake vortex flows. In 24th AIAA Applied Applied Aerodynamics Conference, number AIAA 2006-3479, San Francisco, CA, USA, 5th-8th June 2006.Google Scholar
18. Raffel, M., Willert, C.E. and Kompenhans, J., Particle Image Velocimetry. A Practical Guide, 1998, Springer – Verlag Berlin Heidelberg.Google Scholar
19. White, B.R., Soil transport by winds on Mars, J Geophysical Research, August 1979, 84, pp 4643–4651.Google Scholar