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Transport in the near aerodynamic wakes of flat plates

Published online by Cambridge University Press:  20 April 2006

A. S. M. Maclennan  and
J. H. Vincent
A. S. M. Maclennan
Affiliation:
Department of Applied Physics, University of Strathclyde, Glasgow, Scotland Present address: Sperry Gyroscope, Bracknell, Berks, England.
J. H. Vincent
Affiliation:
Physics Branch, Institute of Occupational Medicine, Edinburgh, Scotland
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Abstract

An experimental investigation has been carried out into the nature of the transport of airborne material in the near aerodynamic wakes of bluff bodies with simple shapes. The main attention was focused on the essential differences existing between axi- symmetric flows (as about disks) and two-dimensional flows (as about rectangular long thin flat plates). Measurements were made for such bodies of the near-wake residence time of injected small particles, along with other and more familiar near- wake properties such as the vortex-shedding frequency and base pressure. It was concluded for disks that the transport of material into and out of the near-wake region is dominated by turbulent diffusion, and is strongly influenced by free-stream turbulence, especially for free-stream turbulence whose length scale is substantially smaller than the disk diameter. For rectangular flat plates, transport is dominated by the periodic shedding of vortices, and to only a secondary extent by turbulent motions, and is not strongly influenced by free-stream turbulence.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 120 , July 1982 , pp. 185 - 197
Copyright
© 1982 Cambridge University Press

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References

Baines, W. D. & Peterson, E. G. 1951 An investigation of flow through screens. Trans. A.S.M.E 73, 467–480.Google Scholar
Bovina, T. A. 1959 Studies of exchange between recirculation zone behind the flame-holder and outer flow. In Proc. 7th Int. Symp. on Combustion, pp. 692–696.
Bradshaw, P. 1974 Effect of free-stream turbulence on turbulent shear layers. Imperial Coll. Aero. Rep. no. 74–10.Google Scholar
Cowdrey, C. F. 1962 A note on the use of end plates to prevent three-dimensional flow at the ends of bluff cylinders. N.P.L. Aero. Rep. no. 1025.Google Scholar
Dryden, H. L., Schubauer, C. B., Mock, W. C. & Skramstad, H. K. 1947 Measurements of intensity and scale of wind tunnel turbulence. NACA Tech. Rep. no. 481.Google Scholar
Fail, R., Lawford, J. A. & Eyre, R. C. W. 1959 Low speed experiments on the wake characteristics of flat plates normal to an air stream. Aero. Res. Counc. R. & M. no. 3120.
Flachsbart, O. 1935 Der Widerstand fuer angeströmter Rechteckplatten bei reynoldsschen Zahlen 1000 bis 6000. Z. angew. Math. Mech. 15, 32–37.Google Scholar
Gerrard, J. H. 1966 The mechanics of the formation region of vortices behind bluff bodies. J. Fluid Mech. 25, 401–413.Google Scholar
Humphries, W. & Vincent, J. H. 1976a An experimental investigation of the detention of airborne smoke in the wake bubble behind a disk. J. Fluid Mech. 73, 452–465.Google Scholar
Humphries, W. & Vincent, J. H. 1976b Experiments to investigate transport processes in the near wakes of discs in turbulent air flow. J. Fluid Mech. 75, 737–749.Google Scholar
Humphries, W. & Vincent, J. H. 1976c Near wake properties of axisymmetric bluff body flows. Appl. Sci. Res. 32, 649–669.Google Scholar
Humphries, W. & Vincent, J. H. 1978 The transport of airborne dusts in the near wakes of bluff bodies. Chem. Engng Sci. 33, 1141–1146.Google Scholar
Hunt, J. C. R. 1973 A theory of turbulent flow round two-dimensional bluff bodies. J. Fluid Mech. 61, 625–706.Google Scholar
Kohan, S. & Schwarz, W. H. 1973 Low speed calibration formula for vortex shedding from cylinders. Phys. Fluids 16, 1528–1529.Google Scholar
Maclennan, A. S. M. & Vincent, J. H. 1981 Particle motion in electrostatic precipitators. In Proc. Conf. on Gas Borne Particles, Oxford, pp. 111–116. Bury St Edmunds, England: Inst. Mech. Engrs.
Strouhal, V. 1878 Ueber eine besondere Art der Tonerregung. Ann. Phys. und Chem., Neue Folge 5, 216–251.Google Scholar
Vincent, J. H. 1977a Particle dynamics in a grid-type electrostatic precipitator. Chem. Engng Sci. 32, 1077–1082.Google Scholar
Vincent, J. H. 1977b Model experiments on the nature of air pollution transport near buildings. Atmos. Environ. 11, 765–774.Google Scholar
Vincent, J. H. 1978 Scalar transport in the near aerodynamic wakes of surface-mounted cubes. Atmos. Environ. 12, 1319–1322.Google Scholar
Vincent, J. H. & MacLennan, A. S. M. 1980 Aerodynamic considerations in electrostatic precipitation. J. Electrostat. 8, 325–342.Google Scholar
Winterfield, G. 1965 On processes of turbulent exchange behind flame holders. In Proc. 10th Int. Symp. on Combustion, pp. 1265–1275.