Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-27T21:55:37.789Z Has data issue: false hasContentIssue false
  • English
  • Français

Close spacing of settling chamber screens

Published online by Cambridge University Press:  04 July 2016

P. E. Hancock  and
A. E. Johnson
P. E. Hancock
Affiliation:
Department of Mechanical Engineering, University of Surrey, Guildford, UK
A. E. Johnson*
Affiliation:
Department of Mechanical Engineering, University of Surrey, Guildford, UK
*
†Now at BP Research, Sunbury-on-Thames, Middlesex, UK.
Get access Rights & Permissions [Opens in a new window]

Extract

Screen separations as little as 0.02 chamber diameters do not adversely affect suppression of mean-flow non-uniformity provided the overall pressure drop coefficient, K, does not exceed about 3.5. At larger K a velocity overshoot develops near the wall boundary layers, which decreases only slowly with wider separation. A simple approximate extension can be made to the theory of Taylor and Batchelor for any number of closely-spaced screens. This shows good agreement with measurements and with low-drag screens predicts perfect attenuation when the overall pressure-drop coefficient is 3.2 or 7.6. Some inferences regarding the effect of close screens on turbulence suppression are also drawn.

Type
Research Article
Information
The Aeronautical Journal , Volume 101 , Issue 1004 , April 1997 , pp. 179 - 183
Copyright
Copyright © Royal Aeronautical Society 1997 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Taylor, G.I. and Batchelor, G.K. The effects of wire gauze on small disturbances in a uniform stream, Q J Mech and Appl Math, 1949, 2, pp 1–29.Google Scholar
2. Bradshaw, P. The effect of wind-tunnel screens on nominally two-dimensional boundary layers, J Fluid Mech, 1965, 22 , pp 679–687.Google Scholar
3. Mehta, R.D. The aerodynamic design of blower wind tunnels with wide angle diffusers, Prog Aerospace Sci, 1977, 18, pp 59–120.Google Scholar
4. Mehta, R.D. and Bradshaw, P. Design rules for small low speed windtunnels, Aeronaut J, November 1979, 83, (827), pp 443–449.Google Scholar
5. Loehrke, R.I. and Nagib, H.M. Control of freestream turbulence by means of honeycombs: A balance between suppression and generation, Trans, ASME J Fluids Eng, 1976, 98, pp 342–353.Google Scholar
6. Dryden, H.L. and Schubauer, G.B. National Bureau of Standards measurements of lateral force on gauzes of round wires. Appendix to Ref. 1, 1949.Google Scholar
7. Elder, J.W. Steady flow through non-uniform gauzes of arbitrary shape, J Fluid Mech, 1959, 5, pp 355–368.Google Scholar
8. Lumley, J.L. Passage of a turbulent stream through honeycomb of large length-to-diameter ratio, J Basic Eng, 1964, 86, pp 218–220.Google Scholar
9. Scheiman, J. and Brooks, J.D. Comparison of experimental and theoretical turbulence reduction from screens, honeycomb, and honeycomb-screen combinations, J Aircr, 1981,18, pp 638–643.Google Scholar
10. Scheiman, J. Considerations for the Installation of Honeycomb and Screens to Reduce Wind Tunnel Turbulence, NASA Report TM-81868, 1981.Google Scholar
11. Groth, J. and Johansson, A.V. Turbulence reduction by screens, J Fluid Mech, 1988, 197, pp 139–155.Google Scholar
12. Dryden, H.L. and Schubauer, G.B. The use of damping screens for the reduction of Wind-tunnel turbulence, J Aero Sci, 1947, 14, pp 221–228.Google Scholar