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Boundary-layer receptivity for a parabolic leading edge

Published online by Cambridge University Press:  26 April 2006

P. W. Hammerton  and
E. J. Kerschen
P. W. Hammerton
Affiliation:
Department of Aerospace & Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA Present address: School of Mathematics, University of East Anglia, Norwich, NR4 7TJ, UK.
E. J. Kerschen
Affiliation:
Department of Aerospace & Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA
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Abstract

The effect of the nose radius of a body on boundary-layer receptivity is analysed for the case of a symmetric mean flow past a body with a parabolic leading edge. Asymptotic methods based on large Reynolds number are used, supplemented by numerical results. The Mach number is assumed small, and acoustic free-stream disturbances are considered. The case of free-stream acoustic waves, propagating obliquely to the symmetric mean flow is considered. The body nose radius, rn, enters the theory through a Strouhal number, S = ωrn/U, where ω is the frequency of the acoustic wave and U is the mean flow speed. The finite nose radius dramatically reduces the receptivity level compared to that for a flat plate, the amplitude of the instability waves in the boundary layer being decreased by an order of magnitude when S = 0.3. Oblique acoustic waves produce much higher receptivity levels than acoustic waves propagating parallel to the body chord.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 310 , 10 March 1996 , pp. 243 - 267
Copyright
© 1996 Cambridge University Press

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