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Concentration fluctuations and fluxes in plumes from point sources in a turbulent boundary layer

Published online by Cambridge University Press:  20 April 2006

J. E. Fackrell
Affiliation:
Marchwood Engineering Laboratories, Central Electricity Generating Board, Marchwood, Southampton, SO4 4ZB, U.K.
A. G. Robins
Affiliation:
Marchwood Engineering Laboratories, Central Electricity Generating Board, Marchwood, Southampton, SO4 4ZB, U.K.

Abstract

Measurements have been made of concentration fluctuations and turbulent fluxes for two passive plumes from an elevated and a ground-level source in a turbulent boundary layer. For the concentration fluctuations, results are presented for the variance, the intermittency, peak values of concentration, probability-density functions and spectra. The balance of terms in the variance transport equation is examined, as is the overall level of fluctuations along the plume. It is shown that most of the production of fluctuations occurs very near the source. Then, the level of fluctuation decays, roughly in accordance with a balance between advection and dissipation. For the turbulent fluxes of concentration, results are presented for the vertical and lateral fluxes, with the associated behaviour of the vertical and lateral eddy diffusivities. The balance of terms in the transport equations for the fluxes is examined. The essential differences between vertical diffusion from ground-level and elevated sources and between near-field and far-field behaviour are shown to be due to the relative importance of the advection and diffusion terms in these equations.

Type
Research Article
Copyright
© 1982 Cambridge University Press

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References

Barry, P. J. 1970 A.E.C.L. Rep. no. 3731.
Becker, H. A., Rosensweig, R. E. & Gwozoz, J. R. 1966 A.I.Ch.E. J. 12, 964972.
Belorgey, M., Nguyen, A. D. & Trinite, M. 1979 Diffusion from a line source in a turbulent boundary layer with transfer to the wall. In Proc. 2nd Symp. on Turbulent Shear Flows, Imperial College, London.
Birch, A. D., Brown, D. R., Dodson, M. G. & Thomas, J. R. 1978 J. Fluid Mech. 88, 431449.
Bradshaw, P. 1976 In Turbulence (ed. P. Bradshaw), pp. 144. Springer.
Chatwin, P. C. & Sullivan, P. J. 1979 J. Fluid Mech. 91, 337355.
Counihan, J. 1969 Atmos. Env. 3, 197214.
Csanady, G. T. 1967 J. Atmos. Sci. 24, 2128.
Deardorff, J. W. 1978 Phys. Fluids 21, 525530.
Durbin, P. A. 1980 J. Fluid Mech. 100, 279302.
Fackrell, J. E. 1978 C.E.G.B. Res. Note R/M/N 1016.
Fackrell, J. E. 1980 J. Phys. E, Sci. Instrum. 13, 888893.
Fackrell, J. E. & Robins, A. G. 1982 Boundary-Layer Met. (to be published).
Freymuth, D. & Uberoi, S. 1973 Phys. Fluids 16, 161168.
Gad-El-Hak, M. & Morton, J. B. 1979 A.I.A.A. J. 17, 558562.
Gifford, F. A. 1959 Adv. Geophys. 6, 117137.
Harter, C. A., Kaiser, G. D., Goddard, A., Gosman, A. D., Ghobadian, A. & El Tahry, S. 1980 In Proc. C.E.C. Seminar on Radioactive releases and their dispersion in the atmosphere, Risø, Denmark.
Hay, J. S. & Pasquill, F. 1959 Adv. Geophys. 6, 345365.
Hunt, J. C. R. & Weber, A. H. 1979 Quart. J. R. Met. Soc. 105, 423443.
Jones, C. D. 1979 In Mathematical Modelling of Turbulent Diffusion in the Environment (ed. C. J. Harris), pp. 277298. Academic.
Launder, B. E. 1976 In Turbulence (ed. P. Bradshaw), pp. 232287. Springer.
Lewellen, W. S. & Teske, M. E. 1976 Boundary-Layer Met. 10, 6990.
O'Brien, E. E. 1978 J. Fluid Mech. 89, 209222.
Pasquill, F. 1974 Atmospheric Diffusion. Ellis-Horwood.
Robins, A. G. 1978 Atmos. Env. 12, 10331044.
Robins, A. G. 1979 J. Ind. Aero. 4, 71100.
Robins, A. G. & Fackrell, J. E. 1979 In Mathematical Modelling of Turbulent Diffusion in the Environment (ed. C. J. Harris), pp. 55114. Academic.
Shlien, D. H. & Corrsin, S. 1976 Int. J. Heat Mass Transfer 19, 285295.
Smith, F. B. & Hay, J. S. 1961 Quart. J.R. Met. Soc. 87, 8291.
Thomas, J. R. 1979 In Mathematical Modelling of Turbulent Diffusion in the Environment (ed. C. J. Harris), pp. 3353. Academic.