Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-20T13:52:58.140Z Has data issue: false hasContentIssue false

An experimental study of sound diffraction at an airfoil trailing edge

Published online by Cambridge University Press:  12 April 2006

S. N. Heavens
Affiliation:
Whittle Laboratory, University of Cambridge

Abstract

Spark photography with a sensitive schlieren system has been used to show the interaction between an incident acoustic wave and the flow around an airfoil trailing edge. Impact of the wave did not show any significant observable effect on the wake or trailing-edge boundary layer. The intensity of the wave diffracted from the edge varied considerably with the prevailing flow conditions. In the event of unsteadiness in the flow or boundary-layer separation the diffracted wave was strongly visible. In smooth flows with attached boundary layers the diffracted wave was very weak. These observations tend to support the recent conclusion of Howe (1976) that trailing-edge flows are quieter if they do not show singular behaviour. This is in contrast to the predictions of earlier theoretical models of the edge diffraction problem.

Type
Research Article
Copyright
© 1978 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

Candel, S. M. 1973 J. Acoust. Soc. Am. 54, 1008.Google Scholar
Crighton, D. G. 1972 Proc. Roy. Soc. A 330, 185.Google Scholar
Davis, S. S. 1975 A.I.A.A. J. 13, 375.Google Scholar
Ffowcs Williams, J. E. & Hall, L. H. 1970 J. Fluid Mech. 40, 657.Google Scholar
Howe, M. S. 1976 J. Fluid Mech. 76, 711.Google Scholar
Jones, D. S. 1972 J. Inst. Math. Appl. 9, 114.Google Scholar
Orszag, S. A. & Crow, S. C. 1970 Stud. Appl. Math. 49, 167.Google Scholar
Poldervaart, L. J., Wijnands, A. P. & Bronkhorst, I. 1974 Film:. Sound Pulse–Boundary Layer Interaction Studies. Technische Hogeschool, Eindhoven, Netherlands. (See Film Reviews, J. Fluid Mech. 78 (1974), 859.)Google Scholar
Sears, W. R. 1976 A.I.A.A. J. 14, 216.Google Scholar
Smirnov, E. P., Kheifets, E. I. & Shenderov, E. L. 1973 Sov. Phys. Acoust. 19, 159.Google Scholar
Tam, C. K. W. 1974 J. Acoust. Soc. Am. 55, 1173.Google Scholar
Thwaites, B. (ed.) 1960 Incompressible Aerodynamics, p. 179. Oxford: Clarendon Press.Google Scholar