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Measurements of Entrainment by a Free Rotating Disc

Published online by Cambridge University Press:  04 July 2016

P. Case*
Affiliation:
University of Liverpool

Summary:

Measurements are presented of the amount of air which flows axially towards the surface of a disc rotating at various speeds when the nature of flow is turbulent.

The method used is similar to that of Ricou and Spalding for the case of the axisymmetrical turbulent jet. The area to one side of the disc is surrounded by a chamber, leaving a small gap between the chamber and the disc. Air is injected into this via a porous baffle until the pressure in the chamber is uniform and atmospheric, a condition which is taken to signify that the “entrainment appetite” of the disc is satisfied.

Existing theories predict the results obtained well at high disc Reynolds numbers, but give greater entrainment rates than experiment at low disc Reynolds numbers. More precise measurements are needed to substantiate these conclusions: in particular the use of a hot-wire anemometer seems essential.

Type
Technical Notes
Copyright
Copyright © Royal Aeronautical Society 1967

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References

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