Skip to main content
SpringerLink
Log in

Dispersion of a Passive Scalar Within and Above an Urban Street Network

  • Research Article
  • Published:
Boundary-Layer Meteorology Aims and scope Submit manuscript

Abstract

The transport of a passive scalar from a continuous point-source release in an urban street network is studied using direct numerical simulation (DNS). Dispersion through the network is characterized by evaluating horizontal fluxes of scalar within and above the urban canopy and vertical exchange fluxes through the canopy top. The relative magnitude and balance of these fluxes are used to distinguish three different regions relative to the source location: a near-field region, a transition region and a far-field region. The partitioning of each of these fluxes into mean and turbulent parts is computed. It is shown that within the canopy the horizontal turbulent flux in the street network is small, whereas above the canopy it comprises a significant fraction of the total flux. Vertical fluxes through the canopy top are predominantly turbulent. The mean and turbulent fluxes are respectively parametrized in terms of an advection velocity and a detrainment velocity and the parametrization incorporated into a simple box-network model. The model treats the coupled dispersion problem within and above the street network in a unified way and predictions of mean concentrations compare well with the DNS data. This demonstrates the usefulness of the box-network approach for process studies and interpretation of results from more detailed numerical simulations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  • Belcher S (2005) Mixing and transport in urban areas. Phil Trans R Soc 363:2947–2968

    Article  Google Scholar 

  • Belcher S, Coceal O, Goulart E, Rudd A, Robins A (2015) Processes controlling atmospheric dispersion through city centres. J Fluid Mech 763:51–81

    Article  Google Scholar 

  • Branford S, Coceal O, Thomas T, Belcher S (2011) Dispersion of a point-source release of a passive scalar through an urban-like array for different wind directions. Boundary-Layer Meteorol 139:367–394

    Article  Google Scholar 

  • Britter R, Hanna S (2003) Flow and dispersion in urban areas. Annu Rev Fluid Mech 35:469–496

    Article  Google Scholar 

  • Carpentieri M, Robins A, Baldi S (2009) Three-dimensional mapping of air flow at an urban canyon intersection. Boundary-Layer Meteorol 133:277–296

    Article  Google Scholar 

  • Coceal O, Dobre A, Thomas T, Belcher S (2007) Mixing and transport in urban areas. J Fluid Mech 589:375–409

    Article  Google Scholar 

  • Coceal O, Goulart E, Branford S, Thomas T, Belcher S (2014) Flow structure and near-field dispersion in arrays of building-like obstacles. J Wind Eng Ind Aerodyn 125:52–68

    Article  Google Scholar 

  • Davidson M, Mylne K, Jones C, Phillips J, Perkins R (1995) Plume dispersion through large groups of obstacles a field investigation. Atmos Environ 29:3245–3256

    Article  Google Scholar 

  • Davidson M, Snyder WH, Lawson R, Hunt J (1996) Wind tunnel simulations of plume dispersion through groups of obstacles. Atmos Environ 30:3715–3725

    Article  Google Scholar 

  • Goulart E (2012) Flow and dispersion in urban areas. PhD thesis, University of Reading

  • Goulart E, Coceal O, Belcher S (2016) Spatial and temporal variability of the concentration field from localized releases in a regular building array. Boundary-Layer Meteorol 159:241–257

    Article  Google Scholar 

  • Hamlyn D, Hilderman T, Britter R (2007) A simple network approach to modelling dispersion among large groups of obstacle. Atmos Environ 41:5848–5862

    Article  Google Scholar 

  • Hanna S, Tehranian S, Carissimo B, Macdonald R, Lohner R (2002) Comparisons of model simulations with observations of mean flow and turbulence within simple obstacle arrays. Atmos Environ 36:5067–5079

    Article  Google Scholar 

  • Hilderman T, Chong R, Kiel D (2007) A laboratory study of momentum and passive scalar transport and diffusion within and above a model urban canopy. Final report Contract Report DRDC Suffield CR 2008-025

  • Macdonald R, Griffiths R, Cheah S (1997) Field experiments of dispersion through regular arrays of cubic structures. Atmos Environ 31:783–795

    Article  Google Scholar 

  • Macdonald R, Griffiths R, Hall D (1998) A comparison of results from scaled field and wind tunnel modelling of dispersion in arrays of obstacles. Atmos Environ 32:3845–3862

    Article  Google Scholar 

  • Milliez M, Carissimo B (2007) Numerical simulations of pollutant dispersion in an idealised urban area, for different meteorological conditions. Boundary-Layer Meteorol 122:321–342

    Article  Google Scholar 

  • Pasquill F (1962) Atmospheric diffusion. The dispersion of windbourne material from industrial and other sources. D. van Nostrand Company Ltd, New York

    Google Scholar 

  • Philips D, Rossi R, Iaccarino G (2013) Large-eddy simulation of passive scalar dispersion in an urban-like canopy. J Fluid Mech 723:404–428

    Article  Google Scholar 

  • Soulhac L (2000) Modelisation de la dispersion atmospheric a l’interieur de la canopee urbaine. PhD thesis, Ecole Centrale de Lyon

  • Soulhac L, Salizzoni P, Cierco FX, Perkins R (2011) The model SIRANE for atmospheric urban pollution dispersion: part I, presentation of the model. Atmos Environ 45(39):7379–7395

    Article  Google Scholar 

  • Soulhac L, Salizzoni P, Mejean P, Didier D, Rios I (2012) The model SIRANE for atmospheric urban pollutant dispersion: part II, validation of the model on a real case study. Atmos Environ 320–337:49

    Google Scholar 

  • Soulhac L, Lamaison G, Cierco FX, Salem NB, Salizzoni P, Mejean P, Armand P, Patryll L (2016) SIRANERISK: modelling dispersion of steady and unsteady pollutant releases in the urban canopy. Atmos Environ 140:242–260

    Article  Google Scholar 

  • Vincent J (1978) Model experiments on the nature of air pollution transport near buildings. Atmos Environ 11:765–774

    Article  Google Scholar 

  • Yee E, Biltoft C (2004) Concentration fluctuation measurements in a plume dispersing through a regular array of obstacles. Boundary-Layer Meteorol 111:363–415

    Article  Google Scholar 

  • Yee E, Gailis R, Hill A, Hilderman T, Kiel D (2006) Comparison of wind tunnel and water-channel simulations of plume dispersion through a large array of obstacles with a scaled field experiment. Boundary-Layer Meteorol 121:389–432

    Article  Google Scholar 

Download references

Acknowledgements

Elisa V. Goulart gratefully acknowledges funding from National Council for Scientific and Technological Development (CNPq) and Espirito Santo Research Foundation (FAPES), Brazil. Omduth Coceal gratefully acknowledges funding from the Natural Environment Research Council (NERC) through their National Centre for Atmospheric Science (NCAS) under Grant No. R8/H12/83/002 and from the Engineering and Physical Sciences Research Council (EPSRC Contract No. EP/K040707/1).

Author information

Author notes

  1. E. V. Goulart

    Present address: Federal University of Espirito Santo, Vitória, Brazil

Authors and Affiliations

  1. Department of Meteorology, University of Reading, P.O. Box 243, Reading, RG6 6BB, UK

    E. V. Goulart & S. E. Belcher

  2. Department of Meteorology, National Centre for Atmospheric Science (NCAS), University of Reading, P.O. Box 243, Reading, RG6 6BB, UK

    O. Coceal

Authors
  1. E. V. Goulart
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. O. Coceal
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. S. E. Belcher
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to E. V. Goulart.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Goulart, E.V., Coceal, O. & Belcher, S.E. Dispersion of a Passive Scalar Within and Above an Urban Street Network. Boundary-Layer Meteorol 166, 351–366 (2018). https://doi.org/10.1007/s10546-017-0315-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10546-017-0315-5

Keywords

Search

Navigation