Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T13:45:26.605Z Has data issue: false hasContentIssue false

Progress towards a theory of jet-flap thrust recovery

Published online by Cambridge University Press:  20 April 2006

P. M. Bevilaqua
Affiliation:
Rockwell International, North American Aircraft Operations, Columbus, Ohio
E. F. Schum
Affiliation:
Rockwell International, North American Aircraft Operations, Columbus, Ohio
C. J. Woan
Affiliation:
Rockwell International, North American Aircraft Operations, Columbus, Ohio

Abstract

A combination of analysis and testing has been utilized to develop a theory of jet-flap thrust recovery at the low speeds and high deflection angles characteristic of V/STOL lift systems. The contribution of jet mixing to the loss of thrust recovery has been computed with a viscid/inviscid interaction analysis. The results of this computation are compared to surface pressure and wake survey measurements made with a two-dimensional jet-flapped airfoil model. It is concluded that the jet-mixing drag causes a small loss of recovery at small values of the jet-thrust coefficient and deflect, an angle. However, at larger values of either jet parameter, the mainstream separates from the airfoil, producing a large loss of recovery. The loss increases suddenly, since it is due to bursting of the leading-edge separation bubble.

Type
Research Article
Copyright
© 1984 Cambridge University Press

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

Bevilaqua, P. M., Cole, P. E. & Schum, E. F. 1980 Progress towards a theory of jet flap thrust recovery. AFOSR Rep. NR80H-76.Google Scholar
Bevilaqua, P. M., Woan, C. J. & Schum, E. F. 1981 Viscid/inviscid interaction analysis of ejector wings. NASA CR-166172.Google Scholar
Davidson, I. M. 1956 The jet flap. J. R. Aero. Soc. January 1956, 2550.Google Scholar
Dimmock, N. A. 1957 Some early jet flap experiments. Aero. Q. November 1957, 331345.Google Scholar
Foley, W. M. 1962 An experimental study of jet flap thrust recovery. PhD thesis, Stanford University; SUDAER 136.
Halsey, N. D. 1974 Method for the design and analysis of jet-flapped airfoils. J. Aircraft 11, 540546.Google Scholar
Hess, J. L. 1973 Higher-order numerical solution of the integral equation for the two-dimensional Neumann problem. Comp. Meth. in Appl. Mech. & Engng 2, 115.Google Scholar
Hunt, I. A. & Joubert, P. N. 1979 Effects of small streamline curvature on turbulent duct flow. J. Fluid Mech. 91, 633659.Google Scholar
Launder, B. E. & Spalding, D. B. 1972 Mathematical Models of Turbulence. Academic.
Leamon, R. G. & Plotkin, A. 1971 An improved solution of the two-dimensional jet-flapped airfoil problem. J. Aircraft 9, 631635.Google Scholar
McCormick, B. W. 1967 Aerodynamics of V/STOL Flight. Academic.
Maskell, E. C. & Spence, D. A. 1959 Theory of the jet flap in three dimensions. Proc. R. Soc. Lond. A 251, 407425.Google Scholar
Metral, A. & Zerner, F. 1953 The Coanda effect. Pub. Sci. et Tech. du Min. de l'Air no. 218 (1948), MOS, TIB/T4027.Google Scholar
Patankar, S. V. & Spalding, D. B. 1970 Heat and Mass Transfer in Boundary Layers. International Textbook Co., Ltd., London.
Quanbeck, A. H. 1963 Further verification of jet flap thrust recovery and identification of its mechanism. PhD thesis, Stanford University; SUDAER 144.
Schlichting, H. 1979 Boundary Layer Theory. McGraw-Hill.
Spence, D. A. 1956 Lift coefficient of a thin, jet-flapped wing. Proc. R. Soc. Lond. A 238, 4668.Google Scholar
Stratford, B. S. 1956a Early thoughts on the jet flap. Aero. Q. February 1956, 4559.Google Scholar
Stratford, B. S. 1956b Mixing and the jet flap. Aero. Q. May 1956, 85105.Google Scholar
Stratford, B. S. 1956c A further discussion on mixing and the jet flap. Aero. Q. August 1956, 169183.Google Scholar
Tsongas, G. E. 1962 Verification and explanation of the controllability of jet flap thrust. Engineering thesis, Stanford University; SUDAER 138.
Williams, J., Butler, S. F. & Wood, M. N. 1961 The aerodynamics of jet flaps. ARC R & M 3304.Google Scholar
Wilson, J. 1973 Thrust augmented wing sections in potential flow. PhD thesis, West Virginia University.
Wyngnanski, I. 1966 The effect of jet entrainment on loss of thrust for a two-dimensional symmetrical jet-flap aerofoil. Aero. Q. 17, 3152.Google Scholar