Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-27T23:03:27.920Z Has data issue: false hasContentIssue false

Experimental investigation of vortex dynamics on a 65° delta wing in sideslip

Published online by Cambridge University Press:  04 July 2016

G. Guglieri
Affiliation:
Politecnico di Torino Dipartimento di Ingegneria Aeronautica e Spaziale, Torino, Italy
F.B. Quagliotti
Affiliation:
Politecnico di Torino Dipartimento di Ingegneria Aeronautica e Spaziale, Torino, Italy

Abstract

The flow structure on the upper side of a delta wing is extremely complex. At moderate angle of attack the flowfield is dominated by organised vortical flow structures emanating from the leading edge. The pressure distribution created on the wing surface by these leading edge vortices causes an increment of lift which may be a relevant percentage of the total wing lift, depending on sweep angle.

Delta wing performance is conditioned, however, by a phenomenon known as vortex breakdown or vortex bursting which appears at high angle of attack. This leads to a drastic change in the flowfield which influences the trend of the aerodynamic coefficients.

With the aim of giving a contribution to the understanding of the phenomenon of vortex breakdown, a 65° delta wing has been extensively tested in the low speed windtunnel of Politecnico di Torino (TPI) both in static and dynamic conditions, under forced oscillatory motions.

Many experiments have been carried out in an effort to understand the factors which can affect the breakdown by varying angle of attack, sideslip angle and Reynolds number.

Flow visualizations have been performed using helium bubble tracers. This technique showed a very good capability for visualizing vortical flows and breakdown, both in static and dynamic conditions.

For the static case, pressure distributions are presented, correlated to force measurements and flow visualizations, at different angles of attack and sideslip for different flow conditions.

For the dynamic case force measurements are shown, compared with flow visualizations, for different angles of attack and for different oscillation frequencies.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1997 

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. Erickson, G.E. and Skow, A.M. Modern fighter aircraft design for high angle of attack maneuvering, AGARD-LS-121, 1982.Google Scholar
2. Earnshaw, P.B. An experimental investigation of the structure of the leading edge vortex, RAE Tech Note Aero 2740, 1961.Google Scholar
3. Greenwell, D.I. and Wood, N. J. Determination of vortex burst location on delta wings from surface pressure measurements, AIAA J, 1992, 30, (11). 4.Google Scholar
4. Lee, M. and Ho, C.M. Lift force of delta wings, Appl Mech Rev, 1990, 43, (9).Google Scholar
5. Wedemeyer, E. Vortex breakdown, AGARD-LS-121, 1982.Google Scholar
6. Gursul, I. Criteria for location of vortex breakdown over delta wings, Aeronautical J, 1995, 99, (985).Google Scholar
7. Brandon, J.M. and Shah, G.H. Effect of large amplitude pitching motions on the unsteady aerodynamic characteristics of flat-plate wings, AIAA Paper 88-4331, 1988.Google Scholar
8. Hall, J.L. An introduction to vortex breakdown and vortex core bursting, NAE-AN-28, Ottawa, 1985.Google Scholar
9. Deluca, L., Guglieri, G., Cardone, G. and Carlomagno, G.M. Experimental analysis of surface flow on a delta wing by infrared thermography, AIAA J, 1995, 33, (8).Google Scholar
10. Fusco, F. and Guglieri, G. Experimental investigation on aircraft dynamic stability parameters, Meccanica, 1992, 28, (1).Google Scholar
11. Guglieri, G. and Quagliotti, F. Dynamic stability derivatives evaluation in a low speed windtunnel, J Aircr, 1993, 30, (3).Google Scholar
12. Weinberg, Z. Effect of Tunnel Walls on Vortex Breakdown Location over Delta Wings, AIAA J, 1992, 30, (6).Google Scholar
13. Lowson, M.V. and Riley, A.J. Vortex breakdown control by delta wing geometry, J Aircr, 1995, 32, (4).Google Scholar
14. Miau, J.J., Kuo, K.T., Liu, W.H., Hsieh, S.J., Chou, J.H. and Lin, C.K. Flow developments above 50-deg sweep delta wings with different leading edge profiles, J Aircr, 1995, 32, (4).Google Scholar
15. Wentz, W.H. and Kohlman, D.L. Vortex breakdown on slender sharp edged delta wings, AIAA Paper 69-778, 1969.Google Scholar
16. Traub, L.W. Simple prediction method for location of vortex break down on delta wings, J Aircr, 1996, 33, (2).Google Scholar
17. Chigier, N.A. Measurement of vortex breakdown over delta wing using a laser anemometer, NEAR-TR-62, 1974.Google Scholar
18. Grismer, D.S., Nelson, R.C. and Ely, W.L. Influence of sideslip on double delta wing aerodynamics, J Aircr, 1995, 32, (2).Google Scholar
19. Jobe, C.H., Hsia, A.H., Jenkins, J.E. and Addington, G.A. Critical states and flow structure on a 65-deg delta wing, J Aircr, 1996, 33, (2).Google Scholar
20. Nelson, R.C., Arena, A.S. and Thompson, S.A. Aerodynamic and flowfield hysteresis of slender wing aircraft undergoing large-amplitude motions, AGARD-CP-497, 1991.Google Scholar
21. Lemay, S.P., Batill, S.M. and Nelson, R.C. Vortex Dynamics on a Pitching Delta Wing, J Aircr, 1990, 27, (2).Google Scholar
22. Gursul, I., Lin, H. and Ho, C.M. Effects of time scales on lift of airfoils in an unsteady stream, AIAA J, 1994, 32, (4).Google Scholar
23. Guglieri, G. and Quagliotti, F. Vortex breakdown study on a 65° delta wing tested in static and dynamic conditions, ICAS paper 92-4.10.2, 1992.Google Scholar