Advertisement

Boundary-Layer Meteorology

, Volume 75, Issue 4, pp 321–352 | Cite as

Fluctuations in dense gas concentrations measured in a wind-tunnel

  • William B. Zimmerman
  • P. C. Chatwin
Article

Abstract

Concentration time series from FID (flame ionisation detector) sensors and catharometers downstream of an instantaneous release of dense gas contaminants are analysed by statistical methods. For each experiment there are either 50 or 100 replications, thus allowing estimates of statistical properties to be made even though the dispersion is nonstationary. The time history of the first four central moments is estimated, and they are plotted against each other, in the manner suggested by Mole and Clarke (1995). The collapse of the skewness-kurtosis plot onto a universal quadratic curve, similar to that found by Mole and Clarke for continuous releases, is observed. In this paper, we show how this observation is consistent with the form of the pdf postulated by Chatwin and Sullivan (1989).

Keywords

Time Series Statistical Method Time History Ionisation Detector Flame Ionisation Detector 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Batchelor, G. K.: 1959, ‘Small-scale variation of convected quantities like temperature in turbulent fluid. Part 1. General discussion and the case of small conductivity’,J. Fluid Mech. 5, 113–133.Google Scholar
  2. Carn, K. K. and Chatwin, P. C.: 1985, ‘Variability and heavy gas dispersion’,J. Haz. Mat. 11, 281–300.Google Scholar
  3. Chatwin, P. C.: 1980, ‘Presentation of longitudinal dispersion data’,J. Hydraulic Div. ASCE,106(HY1, 15150), 71–83.Google Scholar
  4. Chatwin, P. C.: 1982, ‘The use of statistics in describing and predicting the effects of dispersing gas clouds’,J. Haz. Mat. 6, 213–230.Google Scholar
  5. Chatwin, P. C. and Sullivan, P. J.: 1989, ‘The intermittency factor of scalars in turbulence’Phys. Fluids A,1 (4), 761–763.Google Scholar
  6. Chatwin, P. C. and Sullivan, P. J.: 1990, ‘A simple and unifying physical interpretation of scalar fluctuation measurements from many turbulent shear flows’,J. Fluid Mech. 212, 533–556.Google Scholar
  7. Chatwin, P. C., Lewis, D. M., and Mole, N.: 1994, ‘Practical statistical models of environmental pollution’,to appear in Mathematical and Computer Modeling.Google Scholar
  8. Chatwin, P. C., Lewis, D. M., and Sullivan, P. J.: 1995, ‘Turbulent dispersion and the Beta distribution’,submitted to Environmetrics.Google Scholar
  9. Fackrell, J. E. and Robins, A. G.: 1982, ‘Concentration fluctuations and fluxes in plumes from point sources in a turbulent boundary layer’,J. Fluid Mech. 117, 1–26.Google Scholar
  10. Hall, D. J., Waters, R. A., Marsland, G. W., Upton, S. L., and Emmott, M. A.: 1989, ‘Repeat variability in instantaneously released heavy gas clouds-some wind tunnel experiments’, Technical Report LR 804 (PA), Warren Spring Laboratory.Google Scholar
  11. Mylne, K. R. and Mason, P. J.: 1981, ‘Concentration fluctuation measurements in a dispersing plume at a range of up to 1000m’,Quart. J. Roy. Meteorol. Soc.,117, 177–206.Google Scholar
  12. Mole, N. and Clarke, E. D.: 1995, ‘Relationships between the higher moments of concentration and of dose in turbulent dispersion’,Boundary-Layer Meteorol. in press.Google Scholar
  13. McQuaid, J.: 1985, ‘Design of the Thorney Island continuous release trials’,J. Haz. Mat.,16, 1–8.Google Scholar
  14. Pasquill, F.: 1961, ‘The estimation of the dispersion of windborne material’, “Meteorol. Mag.”,90(1063), 33–49.Google Scholar
  15. Pope, S. B.: 1985, ‘Pdf methods for turbulent reactive flows’, “Prog. Energy Combust. Sci.11, 119–192.Google Scholar
  16. Robinson, C.: 1995, ‘An overview of gas dispersion with fences’,School of Mathematics and Statistics, University of Sheffield report no. TR/01/95.Google Scholar
  17. Sawford, B. L. and Sullivan, P. J.: 1995, ‘A simple representation of a developing contaminant concentration field’, “to appear in J. Fluid Mech.”.Google Scholar
  18. Tennekes, H. and Lumley, J. L.: 1972, “A First Course in Turbulence”. MIT Press.Google Scholar
  19. Weil, J.C., Sykes, R. I., and Venkatram, A.: 1992, ‘Evaluating air quality models: review and outlook’J. Appl. Meteorol. 31, 1121–1145.Google Scholar
  20. Zimmerman, W. B. and Chatwin, P. C.: 1995, ‘Statistical fluctuations due to microscale mixing in a diffusion layer’,Environmetrics 6 (6).Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • William B. Zimmerman
    • 1
  • P. C. Chatwin
    • 2
  1. 1.Department of Chemical EngineeringUMISTManchesterUK
  2. 2.Applied Mathematics Section, School of Mathematics and StatisticsUniversity of SheffieldSheffieldUK

Personalised recommendations