Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-13T05:37:04.107Z Has data issue: false hasContentIssue false

Incompressible flow past a flat plate aerofoil with leading edge separation bubble

Published online by Cambridge University Press:  04 July 2016

B. G. Newman
Affiliation:
Department of Mechanical EngineeringMcGill University, Montreal
M-C. Tse
Affiliation:
Department of Mechanical EngineeringMcGill University, Montreal

Summary

A simple flow model has been developed to predict the size of the separation bubble which forms at the sharp leading edge of a flat plate aerofoil at incidence a which are less than about 8°, and the corresponding lift and drag coefficients. This flow model is based on irrotational flow and source singularities which are determined indirectly from experiment. The bubble length is shown to be proportional to α2with a slope which depends on the rate of growth of the separated shear layer. A thin double-wedge aerofoil has been tested in a wind tunnel. It is concluded that these and previous measurements agree fairly well with the theory for chord Reynolds numbers greater than about 0.5 × 106.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1992 

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. Tani, I. Low-speed flows involving bubble separations, Prog Aeronautical Sci, 1964, 5, pp 70103.Google Scholar
2. Inger, G. R. Three-Dimensional Disturbances in Reattaching Separated Flows, AGARD Conference: Göttingen, 1975, CPP- 168, pp 18-1-18-12.Google Scholar
3. Kiya, M. and Sasaki, K. Structure of a turbulent separation bubble, J Fluid Mech, 1983, 137, pp 83113.Google Scholar
4. Mcdonald, H. and Briley, W. R. A Survey of Recent Work on Interacted Boundary-layer Theory for Flow with Separation, in: Numerical and Physical Aspects of Aerodynamic Flows II, Springer-Verlag, New York, 1984, Ch. 6.Google Scholar
5. Kwon, O. K. and Pletcher, R. H. Predictions of Subsonic Separation Bubbles on Aerofoils by Viscous-Inviscid Interaction, in: Numerical and Physical Aspects of Aerodynamic Flows II, Springer-Verlag, New York, 1984, Ch. 7.Google Scholar
6. Cebeci, T. and Clark, R. W. An Interactive Approach to Subsonic Flows with Separation, in: Numerical and Physical Aspects of Aerodynamic Flows II, Springer-Verlag, New York, 1984, Ch. 9.Google Scholar
7. Owen, P. R. and Klanfer, L. On the Laminar Boundary Separation from the Leading Edge of a Thin Aerofoil, TN CP- 220, 1955, ARC.Google Scholar
8. Norbury, J. F. and Crabtree, L. F. A Simplified Model of the Incompressible Flow Past Two-Dimensional Aerofoils, TN Aero. 2352, June 1955, RAE.Google Scholar
9. Savage, S. B. An Approximate Analysis for Reattaching Turbulent Shear Layers in Two-Dimensional Incompressible Flow, Report Ae-3, September 1960, McGill University.Google Scholar
10. Crocco, L. and Lees, L. A mixing theory for the interaction between dissipative flows and nearly isentropic streams, J Aerosp Sci, 1952, 19, (10), pp 649676.Google Scholar
11. Van Ingen, J. L. On the Calculation of Laminar Separation Bubbles in Two-Dimensional Incompressible Flow, AGARD Conference: Göttingen, 1975, CPP-168, pp 11-1-11-16.Google Scholar
12. Stratford, B. S. An experimental flow with zero skin friction throughout its region of pressure rise, J Fuid Mech, 1959, 5, pp 1735.Google Scholar
13. Saffman, P. G. and Sheffield, J. S. Flow over a wing with an attached free vortex, Studies Appl Math, 1977, 57, pp 107117.Google Scholar
14. Milne-Thomson, L. M., Theoretical Hydrodynamics, Macmillan Press, 5th edn. 1968.Google Scholar
15. Gault, D. E. An Investigation at Low Speed of the Flow Over a Simulated Flat Plate at Small Angles of Attack Using Pitot Static and Hot Wire Probes, NACA TN 3876, 1954.Google Scholar
16. Oster, D. and Wygnanski, I. The forced mixing layer between parallel streams, J Fluid Mech, 1982, 123, pp 91130.Google Scholar
17. Prandtl, L. and Tietjens, O. H. Applied Hydro-and Aeromechanics, Dover Publications, 1934, pp 118125.Google Scholar
18. Bradshaw, P. Experimental Fluid Mechanics, Pergamon Press, 1964, pp 135136.Google Scholar
19. Taylor, G. I. Air Resistance of a Flat Plate of Very Porous Material, ARC R&M No. 2236, 1948.Google Scholar
20. Betz, A. Applied Airfoil Theory, (Glauert, H.): Aerodynamic Theory, Vol. IV (ed. Durand), Dover, 1935, pp 2829.Google Scholar
21. O'Meara, M. M. and Mueller, T.J. Laminar separation bubble characteristics on an airfoil at low Reynolds numbers, AIAA J, 1987, 25, pp 10331041.Google Scholar
22. Newman, B. G. and Tse, M-C., Thin Uncambered Aerofoils With a Leading-edge Separation Bubble. Proceedings of the 10th Australasian Fluid Mechanics Conference, Vol. I, pp 8.23-26, 1989.Google Scholar
23. Ruderich, R. and Fernholz, H. H. An experimental investigation of a turbulent shear flow with separation, reverse flow and reattachment, J Fluid Mech, 1986, 163, pp 283322.Google Scholar
24. Terukazu, O. and Masaaki, I. A separated and reattached flow on a blunt flat plate, ASME J Fluids Eng, 1976, 98, pp 7982.Google Scholar
25. Rose, L. M. and Altman, J. M. Low Speed Experimental Investigation of a Thin, Faired, Double-Wedge Airfoil Section with Nose and Trailing-Edge Flaps, NACA TN 1934, August 1949.Google Scholar
26. Rose, L. M. and Altman, J. M. Low Speed Investigation of the Stalling of a Thin, Faired, Double-Wedge Airfoil With Nose Flap, NACA TN 2172, August 1950.Google Scholar
27. Schlichting, H. Boundary-Layer Theory, McGraw Hill, 6th edn., 1968.Google Scholar
28. Squire, H. B. and Young, A. D. The Calculation of Profile Drag on Aerofoils, R&M 1838, 1937.Google Scholar
29. Wallis, R. A. Wind Tunnel Tests on a Series of Circular-Arc Plate Aerofoils, ARL Australia, Aerodynamics Note 74, 1946.Google Scholar
30. Schmitz, F. W. Zur Aerodynamik de kleinen Reynoldszahlen, Jahr 1953 der WGL.Google Scholar
31. Bradshaw, P. and Wong, F. Y. F. The reattachment and relaxation of a turbulent shear layer, J Fluid Mech, 1972, 52, pp 113135.Google Scholar
32. Abramovich, G. N. The Theory of Turbulent Jets. MIT Press, 1963.Google Scholar
33. Glauert, H. The Elements of Aerofoil and Airscrew Theory, Cambridge University Press, 2nd edn, 1947 Google Scholar