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Unsteady aerodynamic loads on an aerofoil with a deflecting tab

Published online by Cambridge University Press:  04 July 2016

J. P. Narkiewicz ,
A. Ling  and
G. T. S. Done
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Abstract

A thin, low cambered aerofoil with a tab at the trailing edge in inviscid, incompressible, two-dimensional, unstalled flow with varying freestream velocity and arbitrary, different motions for both aerofoil and tab is considered. The general expressions for unsteady lift and aerodynamic moment on aerofoil and tab are derived within the assumptions of potential theory.

To verify the approach proposed in this paper, the classical Theodorsen case of an oscillating aerofoil is adopted. For this case, aerofoil loads are calculated in the time domain by applying an inverse Laplace transformation to the approximation of the lift deficiency function in the frequency domain.

The comparison of the results calculated by this method with those obtained by other methods and experiments shows good agreement, which validates the general formulation. The loads on an aerofoil having different frequencies for main aerofoil pitch and tab deflection are calculated.

Type
Research Article
Information
The Aeronautical Journal , Volume 99 , Issue 987 , September 1995 , pp. 282 - 292
Copyright
Copyright © Royal Aeronautical Society 1995 

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Footnotes

1.

Warsaw University of Technology, Warsaw, Poland.

2.

Chinese Helicopter Research and Development Institute, Jingdezhen, Peoples' Republic of China.

3.

City University, London, UK

References

1. Narkiewicz, J. and Done, G.T.S. An overview of smart structure concepts for the control of helicopter rotor, Second European Conference on Smart Structures and Materials, Glasgow, October 1994.Google Scholar
2. Friedmann, P.P. Rotary-wing aeroservoelastic problems, Proceed ings of European Conference on Aeroelasticity, 1991.Google Scholar
3. Yu, Y.H., Lee, S, McAlister, K.W., Tung, CH., and Wanng, C.M. High lift concepts for rotorcraft application, 49th American Helicopter Society Forum, St Louis, May 1993.Google Scholar
4. Theodorsen, T. General theory of aerodynamic instability and the mechanism of nutter, NACA Rep. No. 496, 1935.Google Scholar
5. Greenberg, K.M. Airfoil in sinusoidal motion in a pulsating stream, NACA Rep. No. 1326, 1947.Google Scholar
6. Johnson, W. Application of unsteady airfoil theory to rotary wings, J Aircraft, 1980, 17,(4).Google Scholar
7. Loewy, R.G. A two-dimensional approximation to the unsteady aerodynamics of rotary wings, February 1957, J Aeronaut Sci, 24, (2), pp 81–92.Google Scholar
8. Dinyavari, M.A.H. and Friedmann, P.P. Application of time-domain unsteady aerodynamics to rotary wing aeroelasticity, AIAA J, September 1986, 24, (9).pp 1424–1432.Google Scholar
9. Leishman, J.G. Unsteady lift of an airfoil with a trailing edge flap based on indicial concept, Paper No. 19, Eighteenth European Rotor-craft Forum, Avignon, France, September 1992.Google Scholar
10. Millot, T. and Friedmann, P.P. Vibration reduction in helicopter rotors using an active control surface located on the blade, 33rd AIAA Structures, Structural Dynamics and Materials Conf., Dallas, Texas, April, 1992.Google Scholar
11. Narkiewicz, J. and Rogusz, M. Smart flap for helicopter rotor blade performance improvement, XIX European Rotorcraft Forum, Cemobbio (Como), Italy, September 1993.Google Scholar
12. Dowell, E.H., Curtiss, H.C Jr, Scanlan, R.M. and Sisto, F. A Modern Course in Aeroelasticity, Sijthoff Nordhoff, The Netherlands, 1979.Google Scholar
13. Johnson, W. Helicopter Theory, Princeton University Press, 1980 Google Scholar
14. Spangler, R.L. Jr and Hall, S.R. Piezoelectric actuators for helicopter rotor control, 31 st AIAA Structures, Structural Dynamics and Materials Conference, Long Beach, CA, 2-4 April 1990.Google Scholar
15. van der Vooren, N. Collected Tables and Graphs, AGARD Manual on Aeroelasticity, Vol VI, Part VI, January 1964.Google Scholar
16. Tyler, J.C. and Leishman, J.G. Analysis of pitch and plunge effects on unsteady airfoil behavior, 47th American Helicopter Society Forum, Phoenix, AZ, May 1991.Google Scholar
17. He, CH.J. and du val, R. An unsteady airload model with dynamic stall for rotorcraft simulation, 50th American Helicopter Society Forum, Washington D.C., May 1994.Google Scholar