XFOIL: An Analysis and Design System for Low Reynolds Number Airfoils

  • Mark Drela
Part of the Lecture Notes in Engineering book series (LNENG, volume 54)


Calculation procedures for viscous/inviscid analysis and mixed-inverse design of subcritical airfoils are presented. An inviscid linear-vorticity panel method with a Karman-Tsien compressiblity correction is developed for direct and mixed-inverse modes. Source distributions superimposed on the airfoil and wake permit modeling of viscous layer influence on the potential flow. A two-equation lagged dissipation integral method is used to represent the viscous layers. Both laminar and turbulent layers are treated, with an e 9-type amplification formulation determinining the transition point. The boundary layer and transition equations are solved simultaneously with the inviscid flowfield by a global Newton method. The procedure is especially suitable for rapid analysis of low Reynolds number airfoil flows with transitional separation bubbles. Surface pressure distributions and entire polars are calculated and compared with experimental data. Design procedure examples are also presented.


Separation Bubble Boundary Layer Equation Viscous Layer Airfoil Surface Kutta Condition 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    F. Bauer, P. Garabedian, D. Korn, and A. Jameson Supercritical wing sections I, II, III. In Lecture Notes in Economics and Mathematical Systems, Springer-Verlag, New York, 1972, 1975, 1977.Google Scholar
  2. [2]
    R. E. Melnik, R. R. Chow, and H. R. Mead. Theory of Viscous Transonic Flow Over Airfoils at High Reynolds Number. AIAA-77–680, Jun 1977.Google Scholar
  3. [3]
    M. Drela and M. B. Giles. ISES: A Two-Dimensional Viscous Aerodynamic Design and Analysis Code. AIAA-87–0424, Jan 1987.Google Scholar
  4. [4]
    M. B. Giles and M. Drela. Two-dimensional transonic aerodynamic design method. AIAA Journal, 25(9), Sep 1987.Google Scholar
  5. [5]
    M. Drela and M. B. Giles. Viscous-inviscid analysis of transonic and low Reynolds number airfoils. AIAA Journal, 25(10), Oct 1987.Google Scholar
  6. [6]
    M. Drela. Low-Reynolds number airfoil design for the MIT Daedalus prototype: A case study. Journal of Aircraft, 25(8), Aug 1988.Google Scholar
  7. [7]
    R. J. McGhee, G. S. Jones, and R. Jouty. Performance Characteristics from Wind-Tunnel Tests of a Low-Reynolds-Number Airfoil. AIAA-88–6070, Jan 1988.Google Scholar
  8. [8]
    E. Soinne and S Laine. An inverse boundary element method for single component airfoil design. Journal of Aircraft, 22 (6): 541–543, Jun 1985.CrossRefGoogle Scholar
  9. [9]
    J. L. Kennedy and D. J. Marsden. A potential flow design method for multicomponent airfoil sections. Journal of Aircraft, 15 (1): 47–52, Jan 1978.CrossRefGoogle Scholar
  10. [10]
    R. Eppler and D. M. Somers. A Computer Program for the Design and Analysis of Low-Speed Airfoils. NASA TM 80210, Aug 1980.Google Scholar
  11. [11]
    M. Drela. An Integral Boundary Layer Formulation for Blunt Trailing Edges. AIAA-89–2200, Aug 1989.Google Scholar
  12. [12]
    J. E. Green, D. J. Weeks, and J. W. F. Brooman. Prediction of Turbulent Boundary Layers and Wakes in Compressible Flow by a Lag-Entrainment Method. R & M Report 3791, Aeronautical Research Council, HMSO, London, 1977.Google Scholar
  13. [13]
    T. Cebeci and R. W. Clark. An interactive approach to subsonic flows with separation. In Second Symposium on Numerical and Physical Aspects of Aerodynamic Flows, Long Beach, California, Jan 1983.Google Scholar
  14. [14]
    A. H. Shapiro. Compressible Fluid Flow I. Wiley, New York, 1953.Google Scholar
  15. [15]
    P. H. Cook, M. A. McDonald, and M. C. P. Firmin. Aerofoil RAE 2822 pressure distributions and boundary layer and wake measurements. In Experimental Data Base for Computer Program Assessment, AR-188, AGARD, 1979.Google Scholar

Copyright information

© Springer-Verlag Berlin, Heidelberg 1989

Authors and Affiliations

  • Mark Drela
    • 1
  1. 1.Dept. of Aeronautics and AstronauticsMITCambridgeUSA

Personalised recommendations