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Modelling a helicopter rotor’s response to wake encounters

Published online by Cambridge University Press:  03 February 2016

G. R. Whitehouse  and
R. E. Brown
G. R. Whitehouse
Affiliation:
Department of Aeronautics, Imperial College, London, UK
R. E. Brown
Affiliation:
Department of Aeronautics, Imperial College, London, UK
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Abstract

In recent years, various strategies for the concurrent operation of fixed-and rotary-wing aircraft have been proposed as a means of increasing airport capacity. Some of these strategies will increase the likelihood of encounters with the wakes of aircraft operating nearby. Several studies now exist where numerical simulations have been used to assess the impact of encounters with the wakes of large transport aircraft on the safety of helicopter operations under such conditions. This paper contrasts the predictions of several commonly-used numerical simulation techniques when each is used to model the dynamics of a helicopter rotor during the same idealised wake encounter. In most previous studies the mutually-induced distortion of the wakes of the rotor and the interacting aircraft has been neglected, yielding the so-called ‘frozen vortex’ assumption. This assumption is shown to be valid only when the helicopter encounters the aircraft wake at high forward speed. At the low forward speeds most relevant to near-airfield operations, however, injudicious use of the frozen vortex assumption may lead to significant errors in predicting the severity of a helicopter’s response to a wake encounter.

Type
Research Article
Information
The Aeronautical Journal , Volume 108 , Issue 1079 , January 2004 , pp. 15 - 26
Copyright
Copyright © Royal Aeronautical Society 2004 

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References

1. The potential of rotorcraft to increase airport capacity, 1999, Royal Aeronautical Society Conference, London, October 1999.Google Scholar
2. Dunham, E.R., Holbrook, G.T., Mantay, W.R. Campbell, R.L. and Van Gunst, R.W. Flight test experience of a helicopter encountering an airplane’s trailing vortex, 1976, 32nd Annual National V/STOL Forum of the American Helicopter Society, Washington, DC.Google Scholar
3. Mantay, W.R., Holbrook, G.T., Campbell, R.L. and Tamaine, R.L. Flight investigation of the response of a helicopter to the trailing vortex of a fixed wing aircraft, 1976, AIAA Third Atmospheric Flight Mechanics Conference, Arlington, Texas.Google Scholar
4. Mantay, W.R., Holbrook, G.T., Campbell, R.L. and Tamaine, R.L. Helicopter response of an airplane’s trailing vortex, J Aircr, 1977, 14, (4), pp 357–363.Google Scholar
5. Padfield, G.D. and Turner, G.P. Helicopter encounters with aircraft vortex wakes, 1999, 25th European Rotorcraft Forum, Rome.Google Scholar
6. Padfield, G.D. and Turner, G.P. Helicopter encounters with aircraft vortex wakes, Aeronaut J, January 2001, pp 1–8.Google Scholar
7. Padfield, G.D., Manimala, B. and Turner, G.P. A severity analysis for rotorcraft encounters with vortex wakes, 2002, 28th European Rotorcraft Forum, Bristol.Google Scholar
8. Turner, G.P., Padfield, G.D. and Harris, M. Encounters with aircraft vortex wakes: the impact on helicopter handling qualities, J Aircr, 2002, 39, (5), pp 839–849.Google Scholar
9. Dreier, M.E. The Influence of a Trailing Tip Vortex on a Thrusting Rotor, 1977, MSc Thesis, Penn State University.Google Scholar
10. Mccormick, B.W., Tangler, J.L. and Sherrieb, H.E. Structure of trailing vortices, J Aircr, 1968, 5, (3), pp 260–267.Google Scholar
11. Saito, S., Azuma, A., Kawachi, K. and Okuno, Y. Study of the dynamic response of helicopters to a large airplane wake, 1986, 12th European Rotorcraft Forum, Garmisch-Partenkirchen.Google Scholar
12. Saito, S., Azuma, A., Kawachi, K., Okuno, Y. and Hasegawa, T. Numerical simulations of dynamic response of fixed and rotary wing aircraft to a large airplane wake, 1987, 13th European Rotorcraft Forum, Arles.Google Scholar
13. Azuma, A., Saito, S. and Kawachi, K. Response of a helicopter penetrating the tip vortices of a large airplane, Vertica, 1987, 11, (1), pp 65–76.Google Scholar
14. Azuma, A. and Kawachi, K. Local momentum theory and its application to the rotary wing, J Aircr, 16, (2), 1979, pp 6–14.Google Scholar
15. Kim, K.C., Bir, S.G. and Chopra, I. Helicopter response to an airplane’s vortex wake, 1986, 12th European Rotorcraft Forum, Garmisch-Partenkirchen.Google Scholar
16. Pitt, D.M. and Peters, D.A. Theoretical prediction of dynamic inflow derivatives, Vertica, 1981, 5, pp 21–34.Google Scholar
17. Burnham, D.C. B-747 Vortex alleviation flight tests: ground based sensor measurements, 1982, US DOT/FAA Report DOT-FAA-RD-81-99, January 1982.Google Scholar
18. Curtiss, H.C. and Zhou, Z.G. The dynamic response of helicopters to fixed wing aircraft wake encounters, 1985, Vertical Flight Technology Seminar, Peking, 1985.Google Scholar
19. Johnson, W. Helicopter Theory, 1980, Princeton University Press, New Jersey.Google Scholar
20. Critzos, C.C., Heyson, H. H. and Boswinkle, R.W. Aerodynamic characteristics of NACA 0012 airfoil section at angles-of-attack from 0° to 180°, NACA TN 3361, 1955.Google Scholar
21. Whitehouse, G.R. and Brown, R.E. Modelling a helicopter rotor’s response to encounters with aircraft wakes, 2002, 28th European Rotorcraft Forum, Bristol.Google Scholar
22. Glauert, H. On the horizontal flight of a helicopter, ARC R&M 1157, 1928.Google Scholar
23. Brown, R.E. Rotor wake modeling for flight dynamic simulation of helicopters, AIAA J, 2000, 38, (1), pp 57–63.Google Scholar
24. Brown, R.E. and Houston, S.S. Comparison of induced velocity models for helicopter flight mechanics, J Aircr, 2000, 37, (4), pp 623–629.Google Scholar
25. Schumann, U. and Sweet, R.A. A Direct method for the solution of Poisson’s equation with Neumann boundary conditions on a staggered grid of arbitrary size, J Computational Physics, 1976, 20, (2), pp 171–182.Google Scholar
26. Toro, E.F. A Weighted average flux method for hyperbolic conservation laws, Proceedings of the Royal Society of London, Series A: Mathematical and Physical Sciences, 1989, 423, (1864), pp 401–418.Google Scholar