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Design methodology and performance of an indraft wind tunnel

Published online by Cambridge University Press:  03 February 2016

G. Johl
Affiliation:
Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, UK
M. Passmore
Affiliation:
Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, UK
P. Render
Affiliation:
Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, UK

Abstract

The design methodology and performance of Loughborough University’s new 1·9m × 1·3m, indraft wind tunnel is discussed in the following paper. To overcome severe spatial and financial constraints, a novel configuration was employed, with the inlet and exit placed adjacent to each other and opened to atmosphere. Using a fine filter mesh, honeycomb, two turbulence reduction screens and a contraction ratio of 7·3, flow uniformity in the working area of the jet at 40ms-1 is shown to be within 0·3% deviation from the mean velocity, with turbulence intensity in the region of 0·15%. Working section boundary layer characteristics are shown to be consistent with that of a turbulent boundary layer growing along a flat plate, which originates at the point of inflection of the contraction. A maximum velocity of 46ms-1 was achieved from a 140kW motor, compared to a prediction of 44ms-1, giving an energy ratio of 1·42. Comparison between theoretical and measured performance metrics indicate differences between the way modules perform when part of a wind tunnel system compared to data gathered from test rigs.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2004 

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References

1. Barlow, J. Rae, W.H. and Pope, A. Low Speed Wind Tunnel Testing, 3rd ed, Wiley-Interscience, 1999.Google Scholar
2. Wolf, T. Improvement and modernization of subsonic wind tunnels, J Aircr, 1993, 30, (1), pp 5763.Google Scholar
3. Mehta, R.D. and Bradshaw, P. Design rules for small low speed wind tunnels (Technical Note), Aeronaut J, 1979, pp 443449.Google Scholar
4. Bradshaw, P. and Pankhurst, R.C. The design of low speed wind tunnels, Progress in Aeron Sci, 1964, 5.Google Scholar
5. ESDU 80037, Pressure recovery of axisymmetric intakes at subsonic speeds.Google Scholar
6. Loehrke, R.I. and Nagib, H.M. Experiments on management of free-stream turbulence, (NATO) AGARD Report Number 598.Google Scholar
7. Schieman, J. Comparison of experimental and theoretical turbulence reduction characteristics for screens, honeycomb, and honeycomb-screen combinations, NASA Technical Paper 1958, 1981.Google Scholar
8. Groth, J. and Johansson, A. Turbulence reduction by screens, J. Fluid Mech, 1988, 197, pp 139155.Google Scholar
9. Su, Y. Flow analysis and design of three-dimensional wind tunnel contractions, AIAA J, 1991, 29, (11), pp 19121919.Google Scholar
10. Pankhurst, R.C. and Holder, D.W. Wind Tunnel Technique, Pitman Press, 1968.Google Scholar
11. Morel, T. Comprehensive design of axisymmetric wind tunnel contractions, J Fluids Eng, 1975, pp 225233.Google Scholar
12. Tinkler, J. and Fritz, E. Design of a 5:1 wind tunnel contraction, Canadian Aero and Space J, 1986, 32, (2), pp 108112.Google Scholar
13. Downie, J.H., Jordinson, R. and Barnes, F.H. On the design of three-dimensional wind tunnel contractions, Aeronaut J, 1984, pp 287295.Google Scholar
14. Chmielewski, G.E. Boundary-Layer considerations in the design of aerodynamic contractions, J Aircr, 1974, 11, (8), pp 435438.Google Scholar
15. ESDU 76027, Introduction to Design and Performance Data for Diffusers.Google Scholar
16. ESDU 73024, Performance of conical diffusers in incompressible flow.Google Scholar
17. Sahlin, A. and Johansson, A, Design of guide vanes for minimising the pressure loss in sharp bends, Phys Fluids, 1991, A, 3, (8), pp 19341940.Google Scholar
18. Salter, C., Experiments on thin turning vanes; reports and memoranda No 2469, (Aerodynamics Division NPL), 25 October 1946.Google Scholar
19. Winter, K.G. Comparative tests of thick and thin turning vanes in the Royal Aircraft Establishment 4 × 3ft wind tunnel, reports and memoranda No 2589, August 1947.Google Scholar
20. Johl, G.S., Passmore, M.A. and Render, P.M. Design and performance of wind tunnel turning vanes, (in preparation).Google Scholar
21. Larose, G.L. Tanguay, B. Van Every, D. and Bender, T. The new boundary layer control system for NRC’s 9m x 9m wind tunnel, AIAA-2001-0455.Google Scholar
22. Street, R.L, Elementary Fluid Mechanics, John Wiley and Sons, 1996.Google Scholar