Hostname: page-component-77c89778f8-rkxrd Total loading time: 0 Render date: 2024-07-23T18:29:16.979Z Has data issue: false hasContentIssue false
  • English
  • Français

Optimising wing lift distribution to minimise wake vortex hazard

Published online by Cambridge University Press:  04 July 2016

W. R. Graham
W. R. Graham*
Affiliation:
Department of EngineeringUniversity of Cambridge, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The aim of this work is to investigate how the wake vortex hazard generated by an aircraft can be reduced by modifying the wing lift distribution. The wake associated with a given lift distribution is simulated with a two-dimensional, in viscid ‘vortex method’. A numerical optimisation technique is used to guide the modifications so that a hazard measure, based on the rolling moment induced on a following aircraft encountering the wake, is minimised. The results show that a significant (~20–25%) reduction in hazard compared with conventional high-lift configurations can be achieved, via lift distributions that have a local minimum between the regions contributing to the flap and tip vortices. The counter-signed vorticity associated with this minimum appears to prevent the tip and flap vortices from merging, resulting in a safer wake. Furthermore, the hazard reduction is robust to variations in other features of the lift distribution and should thus be achievable in practice.

Type
Research Article
Information
The Aeronautical Journal , Volume 106 , Issue 1062 , August 2002 , pp. 413 - 426
Copyright
Copyright © Royal Aeronautical Society 2002 

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

1. Glauert, H. The Elements of Aerofoil and Airscrew Theory, 1947, Second Ed, Ch 10, Cambridge University Press.Google Scholar
2. Lanchester, F.W. Aerial flight, Vol 1, Aerodynamics, 1918, Fourth Ed, Ch 4, Constable, London.Google Scholar
3. Rossow, V.J. Lift-generated vortex wakes of subsonic transport aircraft, Prog Aero Sci, 1999, 35, pp 507–660.Google Scholar
4. Spalart, P.R. Airplane trailing vortices, Ann Rev Fluid Mech, 1998, 30, pp 107–138.Google Scholar
5. Crow, S.C. Panel discussion, Aircraft Wake Turbulence and its Detection, 1971, Olsen, J.H., Goldburg, A. and Rogers, M. (Eds), First Ed, pp 577–583, Plenum, New York.Google Scholar
6. Crouch, J.D. Instability and transient growth for two trailing vortex pairs, J Fluid Mech, 350, pp 311–330.Google Scholar
7. Rennich, S.C. and Lele, S.K. Method for accelerating the destruction of aircraft wake vortices, J Aircr, 1999, 36, (2), pp398–404.Google Scholar
8. Crouch, J.D., Miller, G.D. and Spalart, P.R. Active-control system for breakup of airplane trailing vortices, AIAA J, 2001, 39, pp 2374–2381.Google Scholar
9. Ortega, J.M., Bristol, R.L. and Savas, O. Wake alleviation properties of triangular-flapped wings, AIAA J, 2002, 40, pp 709–721.Google Scholar
10. Batchelor, G.K. Axial flow in trailing line vortices, J Fluid Mech, 1964, 20, pp 645–658.Google Scholar
11. Graham, W.R. An assessment of the 2D vortex method in aircraft wake simulation, Aeronaut J, Dec 2001, pp 653–666 Google Scholar
12. Leonard, A. Vortex methods for flow simulation, J Comp Phys, 1980, 37, pp 289–335.Google Scholar
13. Krasny, R. Computation of vortex sheet roll-up in the Trefftz plane, J Fluid Mech, 184, pp 123–155.Google Scholar
14. Graham, W.R. Experimental assessment of the extended Betz method for wake vortex prediction, The Characterisation and Modification of Wakes from Lifting Vehicles in Fluids, AGARD CP584, 1996, pp 9–1 to 9-12.Google Scholar
15. Donaldson, C. Du, P., Snedecker, R.S. and Sullivan, R.D. Calculation of aircraft wake velocity profiles and comparison with experimental measurements, J Aircr, 11, (9), pp 547–555.Google Scholar
16. Devenport, W.J., Rife, M.C., Liapis, S.I. and Follin, G.J. The structure and development of a wing-tip vortex, J Fluid Mech, 312, pp 67–106.Google Scholar
17. Devenport, W.J., Zsoldos, J.S. and Vogel, C.M. The structure and development of a counter-rotating wing-tip vortex pair, J Fluid Mech, 332, pp 71–104.Google Scholar
18. Devenport, W.J., Vogel, C.M. and Zsoldos, J.S. Flow structure produced by the interaction and merger of a pair of co-rotating wing-tip vortices, J Fluid Mech, 394, pp 357–377.Google Scholar
19. Spalart, P.R. Vortex methods for separated flows, NASA TM100068, 1988, Ch 9.Google Scholar