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A Theory on Effect of Entrainment, Due to Jet Flap which Hits the Ground, for an Aerofoil with Separation

Published online by Cambridge University Press:  04 July 2016

T. Kida
Affiliation:
University of Osaka Prefecture, Osaka, Japan
Y. Miyai
Affiliation:
University of Osaka Prefecture, Osaka, Japan

Extract

A number of theoretical methods concerning the flow about jet flapped wings have been developed for predicting the increase of lift due to super-circulation around an aerofoil, but only a few of those methods have been concerned with a jet flapped wing with ground effect.

The main purpose of this paper is to introduce a simple approximate representation of the flow around a jet flapped aerofoil in the case when the jet hits the ground. Hence, it is assumed that the existence of a stationary vortex is neglected and the wake fully develops from the leading edge. It is also assumed that the jet is replaced with a suitable distribution of sinks along the jet axis, to represent the effect of jet entrainment. When the aerofoil is in very close proximity to the ground, it may be assumed that the jet impinges on the ground before the mixing layer finally emerges in the centre of the jet.

Type
Technical Notes
Copyright
Copyright © Royal Aeronautical Society 1971 

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References

1. Spence, D. A. The lift coefficient of a thin, jet-flapped wing. Proceedings of the Royal Society London, Series A, Vol 238, No 121, p. 46, August 1956.Google Scholar
2. Jacobs, W. F. Neuere theoretische Untersuchungen über den Strahlflügel in zweidimensionaler Strömung. Zeitschrift für Flügwissenschaften, 5 Jahrgang, Heft 9, s. 253, September 1957.Google Scholar
3. Spence, D. A. The lift coefficient of a thin, jet-flapped wing II. A solution of integro-differential equation for the slope of the jet. Proceedings of the Royal Society, London, Series A, Vol 261, p. 97, 1961.Google Scholar
4. Lissaman, P. B. S. A Linear Theory for the Jet Flap in Ground Effect. AIAA Paper No 67-2, January 1967.Google Scholar
5. Miyai, Y. and Kida, T. An Approximate Calculating Method of the Flow for a Thin Jet-Flapped Wing with a Small Deflection Angle in Proximity of the Ground. Transactions of the Japan Society for Aeronautical and Space Sciences, Vol 15, No 9, p. 53, 1966.Google Scholar
6. Miyai, Y., Kida, T. and Yasutomi, Z. A Linearized Theory of a Thin Jet-Flapped Aerofoil in Proximity of the Ground. Bulletin of University of Osaka Prefecture, Series A, Vol 17, No 1, p. 21, 1968.Google Scholar
7. Kida, T., Miyai, Y. and Yasutomi, Z. An Aoproximate Analysis for an Aerofoil with a Thin Jet Flap Which Hits the Ground in a Case of Separation from its Leading Edge. Transactions of the Jaoan Society for Aeronautical and Space Sciences, Vol 11, No 18, p. 1, 1968.Google Scholar
8. Huggett, D. J. The Ground Effect on the Jet Flap in Two Dimensions. The Aeronautical Quarterly, Vol X, p. 28, February 1959.Google Scholar
9. Wygnanski, I. and Newman, B. G. The Effect of Jet Entrainment on Lift and Moment for a Thin Aerofoil with Blowing. The Aeronautical Quarterly, Vol XV, p. 122, May 1964.Google Scholar
10. Sawyer, R. A. Two-dimensional reattaching jet flows including the effects of curvature on entrainment. Journal Fluid Mechanics, Vol 17, p. 481, 1964.Google Scholar
11. Stratford, B. S. Mixing and the Jet Flap. The Aeronautical Quarterly, Vol VII, p. 85, May 1956.Google Scholar