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The low-turbulence wind tunnel at Tōhoku University

Published online by Cambridge University Press:  04 July 2016

H. Itō
Affiliation:
The Institute of Fluid Science Tōhoku University, Sendai, Japan
R. Kobayashi
Affiliation:
The Institute of Fluid Science Tōhoku University, Sendai, Japan
Y. Kohama
Affiliation:
The Institute of Fluid Science Tōhoku University, Sendai, Japan

Summary

A general-purpose low turbulence wind tunnel was constructed using the design method of Bradshaw. Sound absorbent material was used in every four corners to decrease sound intensity produced by a fan. The longitudinal component of turbulence intensity at the centre of the closed working section is less than 0.02% of the mean velocity in the speed range between 18 m/s arid 53 m/s. The mean velocity variations across the working section are within ±0.1% of the mean velocity.

Performance measurements have been done at representative tunnel cross sections to clarify the behaviour of flow in the tunnel. This work differs from previous studies in the sense that emphasis is placed not only on velocity distributions, but also on turbulence intensity distributions at several cross sections of the tunnel.

The critical Reynolds number for a flat plate at zero incidence, Rec = 3.5 x 106, measured in a stream of the very low turbulence intensity of 0.016%, is larger than that reported by Schubauer and Skramstad.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1992 

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Footnotes

*

Presently, College of Engineering, Nikōn University, Kōriyama.

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