Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-21T11:04:39.570Z Has data issue: false hasContentIssue false
  • English
  • Français

Active sonic boom control

Published online by Cambridge University Press:  26 April 2006

Steven C. Crow  and
Gene G. Bergmeier
Steven C. Crow
Affiliation:
Aerospace and Mechanical Engineering Department, The University of Arizona, Tucson, AZ 85721, USA
Gene G. Bergmeier
Affiliation:
Aerospace and Mechanical Engineering Department, The University of Arizona, Tucson, AZ 85721, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

A theory and simulation code are developed to study non-steady sources as means to control sonic booms of supersonic aircraft. A key result is that the source of sonic boom pressure is not confined to the length of the aircraft but occupies an extensive segment of the flight path. An aircraft in non-steady flight functions as a synthetic aperture antenna, generating complex acoustic waves with no simple relation to instantaneous volume or lift distributions.

The theory applies linear acoustics to slender non-steady sources but requires no far-field approximation. The solution for pressure contains a term not seen in Whitham's theory for sonic booms of distant supersonic aircraft. The term describes a pressure field that decays algebraically behind the Mach cone and, in the case of steady flight, integrates to a ground load equal to the weight of the aircraft. The algebraic term is separate from those that describe the sonic boom.

Two non-steady source phenomena are evaluated: periodic velocity changes (surge), and periodic longitudinal lift redistribution (slosh). Surge can attenuate a sonic boom and covert it into prolonged weak reverberation, but accelerations needed to produce the phenomenon seem too large for practical use. Slosh may be practical and can alter sonic booms but does not, on average, result in boom attenuation. The conclusion is that active sonic boom abatement is possible in theory but maybe not practical.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 325 , 25 October 1996 , pp. 1 - 28
Copyright
© 1996 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

Cole, J. D. 1953 Note on non-stationary slender body theory. J. Aero Sci. 20, 798–799.Google Scholar
Crow, S. C. 1969 Distortion of sonic bangs by atmospheric turbulence. J. Fluid Mech. 37, 529–563.Google Scholar
Garrick, I. E. & Maglieri, D. J. 1968 A summary of results on sonic-boom pressure-signature variations associated with atmospheric conditions. NASA TN D-4588.Google Scholar
Goldstein, M. E. 1976 Aeroacoustics, pp. 45–53. McGraw-Hill.
Hayes, W. D. 1954 Pseudotransonic similitude and first-order wave structure. J. Aero. Sci. 21, 721–730.Google Scholar
Hayes, W. D. 1971 Sonic boom. Ann. Rev. Fluid Mech. 3, 269–290.Google Scholar
Hayes, W. D., Haefeli, R. C. & Kulstrud, H. E. 1969 Sonic boom propagation in a stratified atmosphere with computer program. NASA Contractor Rep. CR-1299.Google Scholar
Kármán, T. von & Moore, N. B. 1932 Resistance of slender bodies moving with supersonic velocities with special reference to projectiles. Trans. ASME 54, 303–310.Google Scholar
Lamb, H. 1933 Hydrodynamics, 6th Edn. Cambridge University Press.
Landau, L. 1945 On shock waves at large distances from the place of their origin. J. Phys. USSR 9, 496.Google Scholar
Lighthill, M. J. 1952 On sound generated aerodynamically. I. General theory. Proc. R. Soc. Lond. A 211, 564–587.Google Scholar
Lighthill, M. J. 1960 Higher Approximations in Aerodynamic Theory. Princeton University Press.
Prandtl, L. & Tietjens, O. G. 1934 Applied Hydro- and Aeromechanics. Dover.
Seebass, R. 1970 Nonlinear acoustic behavior at a caustic. Third Conf. on Sonic Boom Research, NASA SP-255, pp. 87–120.Google Scholar
Tsien, H. S. 1938 Supersonic flow over an inclined body of revolution. J. Aero. Sci. 5, 480–483.Google Scholar
Whitham, G. B. 1956 On the propagation of weak shock waves. J. Fluid Mech. 1, 290–318.Google Scholar
Whitham, G. B. 1974 Linear and Nonlinear Waves. John Wiley.