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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.

References

1. Bradshaw, P. and Pankhurst, R. C. The design of low-speed wind tunnels. Progress in Aeronautical Sciences, Pergamon Press, 1964, 5, pp 169.Google Scholar
2. Mehta, R. D. and Bradshaw, P. Design rules for small low speed wind tunnels. Aeronaut J, 1979, 83, pp 443449.Google Scholar
3. Itō, H., Kobayashi, R., Yuge, T., Honda, M., Hashimoto, H., Inooka, H., Masuda, H., Takayama, K., Nanbu, K., Imai, K., Sasaki, H., Higano, M., Kohama, Y. and Obinata, G. The design and performance of the low-turbulence wind tunnel, Tōhoku University. Mem lnst High Speed Mech, Tōhoku Univ, (in Japanese), 1980, 44, pp 93151.Google Scholar
4. Kobayashi, R. Design of wind tunnel contractions. Mem Inst High Speed Mech, Tohoku Univ, (in Japanese), 1981, 46, pp 1737 Google Scholar
5. Kohama, Y., Kobayashi, R. and Itō, H. Performance of the small low-turbulence wind tunnel. Mem lnst High Speed Mech, Tōhoku Univ, (in Japanese) 1982, 48, pp 119142.Google Scholar
6. Itō, H., Kobayashi, R., Ōba, R., Tani, J., Masuda, H., Kohama, Y. and Imai, K. The velocity and turbulence distributions in various parts of the low-turbulence wind tunnel, Tōhoku University, Mem lnst High Speed Mech, Tōhoku Univ,(in Japanese), 1985, 54, pp 67104.Google Scholar
7. Rouse, H. and Hassan, M. M. Cavitation-free inlets and contractions. Mech Eng, 1949, 71, pp 213216.Google Scholar
8. Itō, H., Kohama, Y., Imai, K., Hasegawa, S. and Ōta, F. Velocity coefficients for wind-tunnel contractions. Laboratory for Airflow Measurements, lnst High Speed Mech, Tōhoku Univ, (in Japanese), 1985, Technical Note 1.Google Scholar
9. Schuh, H. and Winter, K. G. The R. A. E. 4 ft x 3 ft Experimental Low-Turbulence Wind Tunnel. Part II. Measurements of Turbulence Intensity and Noise in the Working Section. ARC R & M, 1957, No. 2905.Google Scholar
10. Schuh, H. The R.A.E. 4 ft x 3 ft Experimental Low-Turbulence Wind Tunnel. Part IV. Further Turbulence Measurements. ARC R & M, 1962, No. 3261.Google Scholar
11. Schubauer, G. B. and Skramstad, H. K. Laminar-Boundary-Layer Oscillations and Transition on a Flat Plate. NACA Report, 1948, No. 909.Google Scholar
12. Klebanoff, P. S. Characteristics of Turbulence in a Boundary Layer With Zero Pressure Gradient. NACA Report, 1955, No. 1247.Google Scholar
13. Dryden, H. L. and Schubauer, G. B. The use of damping screens for the reduction of wind-tunnel turbulence. J Aeronaut Sci, 1947, 14, pp 221228.Google Scholar
14. Uberoi, M. S. Effect of wind-tunnel contraction on free-stream turbulence. J Aeronaut Sci, 1956, 23, pp 754764.Google Scholar
15. East, L. F. Spatial variations of the boundary layer in a large low-speed wind tunnel. Aeronaut J, 1972, 76, pp 4344.Google Scholar
16. Wieghardt, K. E. G. On the resistance of screens. Aeronaut Q, 1953, 4, pp 186192.Google Scholar
17. Tan-Atichat, J., Nagib, H. M. and Loehrke, R. I. Interaction of free-stream turbulence with screens and grids: a balance between turbulence scales. J Fluid Mech, 1982, 114, pp 501528.Google Scholar
18. Batchelor, G. K. and Townsend, A. A. Decay of turbulence in the final period. Proc R Soc Lond A, 1948, 194, pp 527543.Google Scholar
19. Prandtl, L. Herstellung einwandfreier Luftströme (Windkänale). Handbuch der Experimentalphysik, Akademische Verlagsgesellschaft, Leipzig, 1932, 4, 2.Teil, pp 63106.Google Scholar
20. Batchelor, G. K. and Proudman, I. The effect of rapid distortion of a fluid in turbulent motion. Q J Mech Appl Math, 1954, 7, pp 83103.Google Scholar
21.Clauser, F. H. Turbulent boundary layers in adverse pressure gradients. J Aeronaut Sci, 1954, 21, pp 91108.Google Scholar
22. Daily, J. W. and Harleman, D. R. F. Fluid Dynamics. Addison-Wesley, 1966, p 238.Google Scholar
23. Schlichting, H. und Gersten, K. Berechnung der Strömung in rotationssymmetrischen Diffusoren mit Hilfe der Grenzschichttheorie. Z Flugwiss, 1961, 9, pp 135140.Google Scholar
24. Truckenbrodt, E. Neuere Erkenntnisse über die Berechnung von Strömungsgrenzschichten mittels einfacher Quadraturformeln, Teil I. Ing-Arch, 1973, 43, pp 925.Google Scholar
25. Squire, H. B. and Winter, K. G. The Royal Aircraft Establishment 4 ft x 3 ft Experimental Low Turbulence Wind Tunnel. Part I. General Flow Characteristics. ARC R & M, 1953, No.269Google Scholar
26. Davis, M. R. Design of flat plate leading edges to avoid flow separation. AIAA J, 1980, 18, pp 598600.Google Scholar
27. Schubauer, G. B. and Klebanoff, P. S. Contributions on the Mechanics of Boundary-Layer Transition. NACA Report, 1956, No. 1289.Google Scholar
28. Boltz, F. W., Kenyon, G. C. and Allen, C. Q. The Boundary-Layer Transition Characteristics of Two Bodies of Revolution, a Flat Plate, and an Unswept Wing in a Low-Turbulence Wind Tunnel. NASA Technical Note, 1960, No. D-309.Google Scholar
29. Wells, C. S. Jr., Effects of freestream turbulence on boundary-layer transition. AIAA J, 1967, 5, pp 172174.Google Scholar