Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-22T10:25:05.725Z Has data issue: false hasContentIssue false
  • English
  • Français

A theoretical investigation of enhanced lift in the presence of thin aerofoil stall

Published online by Cambridge University Press:  04 July 2016

W. W. H. Yeung  and
G. V. Parkinson
W. W. H. Yeung
Affiliation:
School of Mechanical and Production EngineeringNanyang Technological University, Singapore
G. V. Parkinson
Affiliation:
Department of Mechanical EngineeringUniversity of British Columbia, Vancouver, Canada
Get access Rights & Permissions [Opens in a new window]

Abstract

A theoretical study is presented for the investigation of a potential-flow model for enhancing lift over a flat-plate aerofoil experiencing thin aerofoil stall. Rather than suppressing the leading-edge separation, flow is assumed to separate tangentially at the leading edge and made to reattach smoothly at the tip of a forward-facing fence joining the plate tangentially on its upper surface to avoid any unnecessary stagnated flow. The length of the fence and its location from the leading edge form two geometrical parameters. At any positive angle of attack, the resulting bounding streamline emanating from the leading edge and terminating at the tip of the fence is simulated by using suitable mathematical singularities subject to boundary conditions such as attaining a finite velocity at each critical point of the conformal mapping involved, and the condition of finite pressure gradient at reattachment, when applicable. Computational results from varying these two geometrical parameters indicate that the lift from each model is enhanced, as compared with the attached flow model around a simple flat plate and the original separated flow model by Kirchhoff.

Type
Research Article
Information
The Aeronautical Journal , Volume 103 , Issue 1023 , May 1999 , pp. 237 - 244
Copyright
Copyright © Royal Aeronautical Society 1999 

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. McCullouoh, G.B. and Gault, D. E. Examples of three representative types of aerofoil-section stall at low speed, NACA TN 2502, 1951.Google Scholar
2. Fage, A. and Johansen, F.C. On the flow of air behind an inclined flat plate of infinite span, Proc R Soc Land, 1927, A 116, pp 170.Google Scholar
3. Kirchhoff, G.J. Reine Angew, Math, 1869, 70, pp 289.Google Scholar
4. Werle, H. Le Tunnel Hydrodynamique au Service de la Recherche Aerospatiale. Pub. No. 156, ONERA, France, 1974. (Photographs 35 and 36 In: Van Dyke, M. An Album of Fluid Motion, The Parabolic Press.)Google Scholar
5. Hurley, D.G. The use of boundary layer control to establish free streamline flows, Adv Aero Sci, 1959, 2, pp 662–708.Google Scholar
6. Hurley, D.G. The use of boundary layer control to establish free streamline flows. Boundary Layer and Flow Control, Vol. 1, (Ed) Lachmann, G.V., Pergamon Press, 1961.Google Scholar
7. Saffman, P.G. and Tanveer, S. Prandtl-Batchelor flow past a flat plate with a forward-facing flap. J Fluid Mech, 1984, 143, pp 351.Google Scholar
8. Saffman, P.G. and Sheffield, J.S. Flow over a wing with an attached free vortex, Studies in Applied Mathematics, 1977, 57, pp 107.Google Scholar
9. Huang, M. and Chow, C. Trapping of a free vortex by Joukowski aerofoils, AIAA J, 1982, 20, pp 292.Google Scholar
10. Rossow, V.J. Lift enhancement by an externally trapped vortex, J Aircr, 1978, 15, (9), pp 618.Google Scholar
11. Rossow, V.J. Two-fence concept for efficient trapping of vortices on aerofoils, J Aircr, 1992, 29, (5), pp 847.Google Scholar
12. Rossow, V.J. Aerodynamics of aerofoils with vortex trapped by two spanwise fences, J Aircr, 1994, 31, (1), pp 146.Google Scholar
13. Woods, L.C. The Theory of Subsonic Plane Flow, Cambridge University Press, 1961.Google Scholar
14. Parkinson, G. V. and Jandali, T.J. A wake source model for bluff body potential flow, J Fluid Mech, 1970, 40, pp 577.Google Scholar
15. Ormsbee, A.I. and Mauohmer, M.D. A class of aerofoils having finite trailing-edge pressure gradients. J Aircr, 1986, 23, pp 97.Google Scholar
16. Parkinson, G.V. and Yeung, W. A wake source model for aerofoils with separated flow. J Fluid Mech, 1987, 179, pp 41.Google Scholar
17. Yeung, W.W.H. and Parkinson, G.V. A wake singularity potential flow model for aerofoils experiencing trailing-edge stall. J Fluid Mech, 1993, 251, pp 203.Google Scholar
18. Traub, L.W. Efficient lift enhancement of a blunt edged delta wing, Aeronaut J, November 1997, 101, (1009) pp 439–445.Google Scholar