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Part II: Steady aerofoil-spoiler characteristics

Published online by Cambridge University Press:  04 July 2016

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Summary

A surface singularity method has been formulated to predict two-dimensional spoiler characteristics at low speeds. Vorticity singularities are placed on the aerofoil surface, on the spoiler surface, on the upper separation streamline from the spoiler tip and on the lower separation streamline from the aerofoil trailing edge. The separation region is closed downstream by two discrete vortices. The flow inside the separation region is assumed to have uniform total head.

The downstream extent of the separated wake is an empirical input. The flows both external and internal to the separated regions are solved.

Theoretical results have been obtained for a range of spoiler-aerofoil configurations which compare reasonably with experimental results.

The model is deficient in that it predicts a higher compression ahead of the spoiler than obtained in practice. Furthermore, there is a minimum spoiler angle below which a solution is not possible; it is thought that this feature is related to the physical observation that at small spoiler angles, the separated flow from the spoiler reattaches on the aerofoil upper surface ahead of the trailing edge.

Type
Inviscid theory of two-dimensional aerofoil/ spoiler configurations at low speed
Information
The Aeronautical Journal , Volume 91 , Issue 908 , October 1987 , pp. 359 - 366
Copyright
Copyright © Royal Aeronautical Society 1987 

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References

1. Mack, M. D., Seetharam, H. C, Kuhn, W. G. and Bright, J. T. Aerodynamics of Spoiler Control Devices. AIAA paper 79-1873, 1979.Google Scholar
2. Wentz, W. H., Ostowaic, C. and Seetharam, H. C. Effects of Design Variable on Spoiler Control Effectiveness, Hinge Moments and Wake Turbulence. AIAA 19th Aerospace Sciences Meeting, January 1981.Google Scholar
3. Consigny, H., Gravelle, A. and Molinaro, R. Aerodynamic Characteristics of a Two-Dimensional Moving Spoiler in Subsonic and Transonic Flow. J Aircraft, September 1984, 21, 9.Google Scholar
4. Mabey, D. G., Welsh, B. L., Stott, G, and Cripps, B. E. The Dynamic Characteristics of Rapidly Moving Spoilers at Subsonic and Transonic Speeds. RAE Report TR 82109, HMSO London, 1982.Google Scholar
5. Siddalingappa, S. R. and Hancock, G. J. Some Qualitative Experiments on the Flow about Aerofoil due to the Unsteady Motion of a Two-Dimensional Spoiler. QMC EP-1036, August 1980.Google Scholar
6. Pfeiffer, N. J. and Zumwalt, G. W. A Computational Model for Low Speed Flows past Aerofoils with Spoilers. AIAA-81-0253, January 1981.Google Scholar
7. Woods, L. C. Theory of Aerofoil Spoilers. ARC R&M 2969, 1953.Google Scholar
8. Barnes, C. S. A Developed Theory of Spoilers on Aerofoils. ARC CP 887, 1965.Google Scholar
9. Jandali, T. and Parkinson, G. V. A Potential Flow Theory for Aerofoil Spoilers. Trans CASI, March 1970, 3, 1, 1–7.Google Scholar
10. Jandali, T. A Potential Flow Theory for Airfoil Spoilers. PhD Thesis, University of British Columbia, 1970.Google Scholar
11. Brown, G. P. Steady and Non-Steady Potential Flow Methods for Aerofoils with Spoilers. PhD Thesis, University of British Columbia, 1971.Google Scholar
12. Hess, J. L. and Smith, A. M. O. Calculation of Potential Flow about Arbitrary Bodies. Prog Aero Sc , Pergamon, 1966, 8.Google Scholar
13. Brown, G. P. and Parkinson, G. V. A Linearised Potential Flow Theory for Aerofoils with Spoilers. Journ Fluid Mech, 1973, 57, 4, 695–719.Google Scholar
14. Parkinson, G. V., Tam Doo, P. and Bernier, R. A. Prediction Method for Spoiler Performance. Society of Automotive Engineers (SAE), 770459, 29th March-lst April 1977.Google Scholar
15. Parkinson, G. V., Brown, G. P. and Jandali, T. The Aerodynamics of Two-Dimensional Airfoil with Spoiler. AGARD CP 143, 1974.Google Scholar
16. Henderson, M. L. A Solution to the 2-D Separated Wake Modelling Problem and its use to Predict CLmax of Arbitrary Airfoil Sections. AIAA paper 78-159, January 1978.Google Scholar
17. Parkinson, G. V. and Tam Doo, P. Prediction of Aerodynamic Effects of Spoilers on Wings. AGARD CP 204, 1976.Google Scholar
18. Maskew, B. and Dvorak, F. A. The Prediction of CLmax using a Separated Flow Model. Journal of American Helicopter Society, April 1978.Google Scholar
19. Tou, H. B. and Hancock, G. J. Supplement to an Inviscid Model Prediction of Steady Two-Dimensional Aerofoil-Spoiler Characteristics at Low Speeds. QMC EP-1056, 1983.Google Scholar