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Simplification of the Razor Blade Technique and its Application to the Measurement of Wall-Shear Stress in Wall-Jet Flows

Published online by Cambridge University Press:  07 June 2016

B. R. Pai
Affiliation:
Imperial College, London
J. H. Whitelaw
Affiliation:
Imperial College, London
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Summary

Experiments in a in (6-35 mm) channel have yielded further information on the precision and convenience of the razor blade technique. It is shown that adhesive tape or carefully located cement can be used to secure a segment of razor blade over a static pressure hole: the resulting calibration for shear stress remains valid if the blade is removed and relocated over the same or a different, similar sized hole. Razor blade segments, calibrated in this manner, have been used to measure wall-shear stress in a turbulent boundary layer with tangential, secondary injection: the results indicate that V. C. Patel’s law of the wall is valid for such flows.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1964

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