Author:
Berman C. H.,Williams J. E. Ffowcs
Abstract
A linearized analysis of the two-dimensional double vortex sheet model of a jet shows that inviscid jet instabilities occur over a wide range of frequencies at all jet Mach numbers. No particular frequency for maximum growth rate exists unless finite shear layer thickness effects are considered. It is suggested that the model describes the essential characteristics of a real jet disturbed by long wavelength perturbations. The idea is advanced that the jet flow constitutes a broad band amplifier of high gain. Disturbances can grow rapidly to a size when nonlinear effects bring about significant interaction with the mean flow. By seeding the jet with disturbances of a type that are highly amplified it is argued that gross features of the flow may be affected and that the jet may be rendered less noisy at high Mach number. It is argued that some of these ideas are supported by the observation that a supersonic jet diffuses at an unusually rapid rate when subject to the oscillatory condition known as ‘screech’.
Publisher
Cambridge University Press (CUP)
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics
Reference9 articles.
1. Lighthill, M. J. 1962 Sound generated aerodynamically. The Bakerian Lecture 1961.Proc. Roy. Soc. A267,147–183.
2. Miles, J. W. 1958 On the disturbed motion of a plane vortex sheet.J. Fluid Mech. 4,538.
3. Fejer, J. A. & Miles, J. W. 1963 On the stability of a plane vortex sheet with respect to three-dimensional disturbances.J. Fluid Mech. 15,335.
4. Graham, E. W. & Graham, B. B. 1968 The effect of a shear layer on plane waves of sound in a fluid.Boeing Scientific Res. Labs. D1-82–0823.
5. Miles, J. W. 1956 On the reflection of sound at an interface of relative motion.J. Acoust. Soc. Am. 29,226.
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