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A Calculation Method for Circulation Control by Tangential Blowing Around a Bluff Trailing Edge

Published online by Cambridge University Press:  07 June 2016

R. J. Kind*
Affiliation:
Engineering Laboratory, University of Cambridge
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Summary

The flow near the trailing edge of a circulation-controlled aerofoil is studied. The circulation is controlled by tangential blowing around the bluff trailing edge of the aerofoil.

Velocity profiles in the blowing jet on the trailing edge of a circulation-controlled aerofoil have been measured and a calculation method has been developed for this type of circulation control. The development of the blowing jet is calculated by means of a velocity-profile equation, an angular-momentum integral equation, and an entrainment equation. Improved criteria are suggested for establishing the starting conditions for the development calculation. A realistic method is presented for taking into account the effects of the boundary layer which develops upstream of the blowing slot. A separation criterion for turbulent wall jets and a curvature correction for the entrainment rate are proposed. The calculated blowing-jet developments are found to be in good agreement with experiment. There is fair agreement between the calculated and measured blowing rates required to produce given lift coefficients on the aerofoil.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1968

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References

1. Kind, R. J. and Maull, D. J. An experimental investigation of a low-speed circulation-controlled aerofoil. Aeronautical Quarterly, Vol. XIX, p. 170, May 1968.Google Scholar
2. Fekete, G. I. Coanda flow of a two-dimensional wall jet on the outside of a circular cylinder. McGill University Mechanical Engineering Department Report 63-11, 1963.Google Scholar
3. Dunham, J. A tentative theory of circulation control applied to a circular cylinder. ARC 27 170, 1965. To be published.Google Scholar
4. Spalding, D. B. A unified theory of friction, heat transfer and mass transfer in the turbulent boundary layer and wall jet. ARC 25 925, 1964.Google Scholar
5. Escudier, M. P. and Nicoll, W. B. The entrainment function in turbulent boundary-layer and wall-jet calculations. Journal of Fluid Mechanics, Vol. 25, p. 337, 1966.CrossRefGoogle Scholar
6. Head, M. R. Entrainment in the turbulent boundary layer. ARC R & M 3152, 1958.Google Scholar
7. Guitton, D. E. Two-dimensional turbulent wall jets over curved surfaces. McGill University Mechanical Engineering Department Report 64-7, 1964.Google Scholar
8. Gartshore, I. S. The streamwise development of two-dimensional wall jets and other two-dimensional turbulent shear flows. PhD Thesis, McGill University Mechanical Engineering Department, 1965.Google Scholar
9. Stratford, B. S. The prediction of separation of the turbulent boundary layer. Journal of Fluid Mechanics, Vol. 5, p. 1, 1959.Google Scholar
10. Stratford, B. S. An experimental flow with zero skin friction throughout its region of pressure rise. Journal of Fluid Mechanics, Vol. 5, p. 17, 1959.CrossRefGoogle Scholar
11. Kind, R. J. A proposed method of circulation control. PhD Thesis, University of Cambridge, 1967.Google Scholar

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