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Cumulative nonlinear distortion of an acoustic wave propagating through non-uniform flow

Published online by Cambridge University Press:  12 April 2006

M. Kurosaka
Affiliation:
Research and Development Center, General Electric Company, Schenectady, New York 12301
Present address: University of Tennessee Space Institute, Tullahoma, Tennessee 37388.

Abstract

In this paper we examine how the unsteady flow field radiated from an oscillating body is altered from the result of acoustic theory as the direct consequence of disturbances propagating through the non-uniform flow produced by the presence of the body. Taking the specific example of an oscillating airfoil placed in supersonic flow and having the contour of a parabolic arc, we derive a closed-form representation for the unsteady flow field in terms of the confluent hypergeometric function. The analytical expression reveals explicitly that, though the body shape has a negligible effect in the near field, it inextricably affects the unsteady flow at a large distance, both in its amplitude and phase, and substantially modifies the results of acoustic theory. In addition, we display the relation of this solution to the ‘fundamental solution’ and the other salient physical features connected with disturbances propagating through non-uniform flow. The present results recover Whitham's rule in the limit of zero frequency of oscillation and also include, as another special case, the unsteady solution for a wedge obtained by Carrier and Van Dyke.

Type
Research Article
Copyright
© 1977 Cambridge University Press

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References

Abramowitz, M. & Stegun, I. A. 1964 Handbook of Mathematical Functions. Washington: Nat. Bur. Stand.
Budden, K. G. 1961 Radio Waves in Ionosphere. Cambridge University Press.
Carrier, G. F. 1949 J. Aero. Sci. 16, 150.
Courant, R. & Friedrichs, K. O. 1948 Supersonic Flow and Shock Waves. Interscience.
Courant, R. & Hilbert, D. 1962 Methods of Mathematical Physics, vol. 2. Interscience.
Erdélyi, A., Magnus, W., Oberhettinger, F. & Tricorni, F. G. 1954 Tables of Integral Transforms, vol. 1. McGraw-Hill.
Friedrichs, K. O. 1948 Comm. Pure Appl. Math. 1, 211.
Goldstein, M. E. & Atassi, H. 1976 J. Fluid Mech. 74, 741.
Goldstein, M. E. & Rice, E. 1973 J. Sound Vib. 30, 79.
Hayes, W. D. 1954 J. Aero. Sci. 21, 721.
Kurosaka, M. 1974 J. Fluid Mech. 62, 811.
Kurosaka, M. 1975 A.I.A.A. J. 13, 1514.
Lesser, M. B. 1970 J. Acoust. Soc. Am. 47, 1297.
Lighthill, M. J. 1949 Phil. Mag. 40, 1179.
Lighthill, M. J. 1954 High approximations. In General Theory of High Speed Aerodynamics and Jet Propulsion, chap. E. Princeton University Press.
Lin, C. C. 1954 J. Math. & Phys. 33, 117.
Miles, J. W. 1959 The Potential Theory of Unsteady Supersonic Flow. Cambridge University Press.
Nayfeh, A. H. 1975 J. Acoust. Soc. Am. 57, 1413.
Oswatitsch, K. 1962 Arch. Mech. Stosowanej 14, 621.
Romanova, N. N. 1970 Izv. Atmos. Ocean. Phys. 6, 134.
Slater, L. J. 1960 Confluent Hypergeometric Functions. Cambridge University Press.
Temple, G. & Jahn, H. A. 1945 Aero. Res. Counc. R. & M. no. 2140.
Tricomi, F. G. 1949 Ann. Mat. Pura Appl. 4, 263.
Van Dyke, M. 1953a N.A.C.A. Rep. no. 1183.
Van Dyke, M. 1953b Quart. Appl. Math. 11, 360.
Van Dyke, M. 1975 Perturbation Methods in Fluid Mechanics, annotated ed. Parabolic Press.
Whitham, G. B. 1950 Proc. Roy. Soc. A 201, 89.
Whitham, G. B. 1952 Comm. Pure Appl. Math. 5, 301.
Whitham, G. B. 1975 Linear and Nonlinear waves. Wiley.