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Vortex shedding from a blunt trailing edge with equal and unequal external mean velocities

Published online by Cambridge University Press:  29 March 2006

D. R. Boldman ,
P. F. Brinich  and
M. E. Goldstein
D. R. Boldman
Affiliation:
NASA Lewis Research Center, Cleveland, Ohio 44135
P. F. Brinich
Affiliation:
NASA Lewis Research Center, Cleveland, Ohio 44135
M. E. Goldstein
Affiliation:
NASA Lewis Research Center, Cleveland, Ohio 44135
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Abstract

A flow-visualization study has shown that strong Kármán vortices develop behind the blunt trailing edge of a plate when the free-stream velocities over both surfaces are equal and that the vortices tend to disappear when the surface velocities are unequal. This observation provides an explanation for the occurrence and disappearance of certain discrete tones often found to be present in the noise spectra of coaxial jets. Both the vortex formation and the tones occur at a Strouhal number based on the lip thickness and the average of the external steady-state velocities of about 0.2.

Results from theoretical calculations of the vortex formation, based on an inviscid incompressible analysis of the motion of point vortices, were in good agreement with the experimental observations.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 75 , Issue 4 , 25 June 1976 , pp. 721 - 735
Copyright
© 1976 Cambridge University Press

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References

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