Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-08T00:24:01.618Z Has data issue: false hasContentIssue false
  • English
  • Français

Vortex flows on UAVs: Issues and challenges

Published online by Cambridge University Press:  03 February 2016

I. Gursul
I. Gursul*
Affiliation:
Department of Mechanical Engineering, University of Bath, Bath, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Separated and vortical flows are dominant over various unmanned air vehicles (UAVs). In this article, issues and challenges of vortical flows for future UAVs are reviewed. These include shear layer instabilities, vortex breakdown and wing stall, vortex interactions, nonslender vortices, multiple vortices, and manoeuvring wing vortices. There are also issues relating to vortical flows in certain flow/structure interactions, as well as in aerodynamics/propulsion interactions. Separated and vortical flows are even more dominant at low Reynolds number flows. The main features of vortical flows, unsteady aerodynamics, and propulsion related vortical flow isssues relevant to mini- and micro air vehicles, are discussed.

Type
Research Article
Information
The Aeronautical Journal , Volume 108 , Issue 1090 , December 2004 , pp. 597 - 610
Copyright
Copyright © Royal Aeronautical Society 2004 

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. Gad-El-Hak, M. and Blackwelder, R.F. The discrete vortices from a delta wing, AIAA J, 1985, 23, pp 961–962.Google Scholar
2. Riley, A.J. and Lowson, M.V. Development of a three-dimensional free shear layer, J Fluid Mechanics, 1998, 369, pp 49–89.Google Scholar
3. Mitchell, A.M. and Molton, P. Vortical substructures in the shear layers forming leading-edge vortices, AIAA J, 2002, 40, (8), pp 1689–1692.Google Scholar
4. Visbal, M.R. Computational and physical aspects of UAV vortical flows, Workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK. See also, Visbal, M.R. and Gordnier, R.E., On the structure of the shear layer emanating from a swept leading edge at angle-of-attack, AIAA-2003-4016, 33rd Fluid dynamics conference and exhibit, 23-26 June 2003, Orlando, FL, USA.Google Scholar
5. Hall, M.G. Vortex breakdown, Annual review of fluid mechanics, 1972, 4, pp 195–218.Google Scholar
6. Leibovich, S. Vortex stability and breakdown: survey and extension, AIAA J, 1984, 22, (9), pp 1192–1206.Google Scholar
7. Delery, J.M. Aspects of vortex breakdown, Progress in Aerospace Sciences, 1994, 30, pp 1–59.Google Scholar
8. Morton, S. High resolution computational unsteady aerodynamic techniques applied to maneuvering unmanned combat aircraft, workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK. See also, CEAS Aerospace Aerodynamics Research Conference, 10-12 June 2003, London, UK.Google Scholar
9. Earnshaw, P.B. and Lawford, J.A. Low speed wind tunnel experiments on a series of sharp-edged delta wings, R&M 3424, August 1964.Google Scholar
10. Pemberton, T. Aspects of use of CFD for configuration design of UAV concepts, Workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK.Google Scholar
11. Gursul, I. Unsteady flow phenomena over delta wings at high angle-of-attack, AIAA J, February 1994, 32, (2), pp 225–231.Google Scholar
12. Gursul, I. and Xie, W. Buffeting flows over delta wings, AIAA J, 1999, 37, (1), pp 58–65.Google Scholar
13. Menke, M. and Gursul, I. Unsteady nature of leading edge vortices, Physics of Fluids, 1997, 9, (10), pp 1–7.Google Scholar
14. Gursul, I. Review of unsteady vortex flows over slender delta wings, J Aircr, in print. See also, AIAA-2003-3942, AIAA Applied Aerodynamics Conference, 23-26 June, 2003, Orlando, FL, USA.Google Scholar
15. Menke, M., Yang, H. and Gursul, I. Experiments on the unsteady nature of vortex breakdown over delta wings, Experiments in Fluids, 1999, 27, (3), pp 262–272.Google Scholar
16. Gray, J.M., Gursul, I. and Butler, R. Aeroelastic response of a flexible delta wing due to unsteady vortex flows, AIAA-2003-1106, 41st Aerospace Sciences Meeting and Exhibit, 6-9 January 2003, Reno, NV, USA.Google Scholar
17. Taylor, G., Schnorbus, T. and Gursul, I. An investigation of vortex flows over low sweep delta wings, AIAA-2003-4021, AIAA Fluid Dynamics Conference, 23-26 June 2003, Orlando, FL, USA.Google Scholar
18. Gordnier, R.E. and Visbal, M.R. Higher-order compact difference scheme applied to the simulation of a low sweep delta wing flow, AIAA-2003-0620, 41st Aerospace Sciences Meeting and Exhibit, 6-9 January 2003, Reno, NV, USA.Google Scholar
19. Matsuno, T. and Nakamura, Y. Self-induced roll oscillation of 45-degree delta wing, AIAA-2000-0655, 38th AIAA Aerospace Sciences Meeting and Exhibit, 10-13 January 2000, Reno, NV, USA.Google Scholar
20. Gad-El-Hak, M. and Ho, C.M. The pitching delta wing, AIAA J, 1985, 23, (11), pp 1660–1665.Google Scholar
21. Rockwell, D. Three-dimensional flow structure on delta wings at high angle-of-attack: experimental concepts and issues, AIAA Paper 93-0550, January 1993.Google Scholar
22. Visbal, M.R. Computational and physical aspects of vortex breakdown on delta wings, AIAA Paper 95-0585, January 1995.Google Scholar
23. Gursul, I. Proposed mechanism for time lag of vortex breakdown location in unsteady flows, J Aircr, 2000, 37, (4), pp 733–736.Google Scholar
24. Gordnier, R. High-fidelity computational simulation of nonlinear fluid-structure interaction problems, workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK. See also, Gordnier, R. and Melville, R., Numerical simulation of limit-cycle oscillations of a cropped delta wing using the full navier-stokes equations, Int J Computational Fluid Dynamics, 2001, 14, (3), pp 211–224.Google Scholar
25. Taylor, G.S. and Gursul, I. Buffeting flows over a low sweep delta wing, AIAA J, September 2004, 42, (9), pp 1737–1745. See also, Unsteady vortex flows and buffeting of a low sweep delta wing, AIAA-2004-106, 42nd Aerospace Sciences Meeting and Exhibit, 5-8 January 2004, Reno, NV.Google Scholar
26. Taylor, G.S. and Gursul, I. Lift enhancement over a flexible delta wing, AIAA-2004-2618, 2nd AIAA Flow Control Conference, June 2004, Portland, Oregon.Google Scholar
27. Phillips, S., Lambert, C. and Gursul, I. Effect of a trailing-edge jet on fin buffeting, J Aircr, 2003, 40, (3), pp 590–599.Google Scholar
28. Shyy, W. Membrane wing aerodynamics for MAV applications, workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK.Google Scholar
29. Laitone, E.V. Aerodynamic lift at Reynolds numbers below 7 × 104 , AIAA J, September 1996, 34, (9), pp 1941–1942.Google Scholar
30. Gursul, I., Taylor, G. and Wooding, C.L. Vortex flows over fixed-wing micro air vehicles, AIAA-2002-0698, 40th AIAA Aerospace Meeting and Exhibit, 14-17 January 2002, Reno, NV, USA.Google Scholar
31. Torres, G.E. and Mueller, T.J. Aerodynamic characteristics of low aspect ratio wings at low reynolds numbers, Proceedings of the conference: Fixed, flapping and rotary wing vehicles at very low Reynolds Numbers, Univ of Notre Dame, Notre Dame, IN, 5-7 June 2000, pp 228–305.Google Scholar
32. Hebbar, S.K., Platzer, M.F. and Fritzelas, A.E. Reynolds number effects on the vortical-flow structure generated by a double-delta wing, Experiments in fluids, 2000, 28, pp 206–216.Google Scholar
33. Shyy, W., Berg, M. and Ljungqvist, D. Flapping and flexible wings for biological and micro air vehicles, Progress in Aerospace Sciences, 1999, 35, pp 455–505.Google Scholar
34. Wooding, C.L. and Gursul, I. Unsteady aerodynamics of low aspect ratio wings at low reynolds numbers, Royal Aeronautical Society Aerospace Aerodynamics Research Conference, 10-12 June, 2003, London.Google Scholar
35. Lighthill, M.J. Aerodynamic Aspects of Animal Flight, in Swimming and Flying in Nature, 2, ed. Wu, Y-T, Brokaw, C.J. and Brennen, C. pp 423–491. New York/London:Plenum, 1975.Google Scholar
36. Mueller, T.J. and Delaurier, J.D. Aerodynamics of small vehicles, Annual Review of Fluid Mechanics, 2003, 35, pp 89–111.Google Scholar
37. Maxworthy, T. The fluid dynamics of insect flight, Annual Review of Fluid Mechanics, 1981, 13, pp 329–350.Google Scholar
38. Ellington, C. Insect flight and MAVs, Workshop on aerodynamic issues of unmanned air vehicles, 4-5 November 2002, University of Bath, UK.Google Scholar
39. Jones, K.D. and Platzer, M.F. Flapping wing propulsion for a micro air vehicle, AIAA-2000-0897, 38th Aerospace Sciences Meeting and Exhibit, 10-13 January 2000, Reno, NV.Google Scholar
40. Jones, K.D., Dohring, C.M. and Platzer, M.F. Experimental and Computational Investigation of the Knoller-Betz Effect, AIAA J, May 1998, 36, (7), pp 1240–1246.Google Scholar
41. Jones, K.D., Lund, T.C. and Platzer, M.F. Experimental and computational investigation of flapping wing propulsion for micro air vehicles, Chapter 16 in Fixed and Flapping Wing Aerodynamics for Micro air Vehicle Applications, Mueller, T.J. (Ed) pp 307–339, published by AIAA, 2001.Google Scholar
42. Heathcote, S., Martin, D. and Gursul, I., flexible flapping airfoil propulsion at zero freestream velocity, AIAA J, November 2004, 42, (11), pp 2196–2204. See also, AIAA-2003-3446, AIAA Fluid Dynamics Conference, 23-26 June 2003, Orlando, FL.Google Scholar
43. Whitehead, J. and Gursul, I. Aerodynamics and propulsion of synthetic jet based micro air vehicles, AIAA-2003-4004, AIAA Fluid Dynamics Conference, 23-26 June, 2003, Orlando, FL.Google Scholar
44. Whitehead, J. and Gursul, I. Interaction of synthetic jet propulsion with wing aerodynamics at low reynolds numbers, AIAA-2004-0093, 42nd Aeropsace Sciences Meeting and Exhibit 3-8 January 2004, Reno, Nevada.Google Scholar