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Boundary-Layer Meteorology

, Volume 137, Issue 2, pp 187–204 | Cite as

Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

  • Xian-Xiang LiEmail author
  • Rex E. Britter
  • Tieh Yong Koh
  • Leslie K. Norford
  • Chun-Ho Liu
  • Dara Entekhabi
  • Dennis Y. C. Leung
Open Access
Article

Abstract

Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification was produced by heating the ground of the street canyon. Using the Boussinesq approximation, thermal buoyancy forces were taken into account in both the Navier–Stokes equations and the transport equation for subgrid-scale turbulent kinetic energy (TKE). The LESs were validated against experimental data obtained in wind-tunnel studies before the model was applied to study the detailed turbulence, temperature, and pollutant dispersion characteristics in the street canyon of aspect ratio 1. The effects of different Richardson numbers (Ri) were investigated. The ground heating significantly enhanced mean flow, turbulence, and pollutant flux inside the street canyon, but weakened the shear at the roof level. The mean flow was observed to be no longer isolated from the free stream and fresh air could be entrained into the street canyon at the roof-level leeward corner. Weighed against higher temperature, the ground heating facilitated pollutant removal from the street canyon.

Keywords

Ground heating Large-eddy simulation Pollutant dispersion Unstable stratification Urban street canyon 

Notes

Acknowledgements

This project was funded by Singapore National Research Foundation (NRF) through the Singapore-MIT Alliance for Research and Technology (SMART) Center for Environmental Sensing and Modeling (CENSAM).

Open Access

This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

References

  1. Baik JJ, Kim JJ (1999) A numerical study of flow and pollutant dispersion characteristics in urban street canyons. J Appl Meteorol 38: 1576–1589CrossRefGoogle Scholar
  2. Britter RE, Hanna SR (2003) Flow and dispersion in urban areas. Annu Rev Fluid Mech 35: 469–496CrossRefGoogle Scholar
  3. Ca VT, Asaeda T, Ito M, Armfield S (1995) Characteristics of wind field in a street canyon. J Wind Eng Ind Aerodyn 57(1): 63–80CrossRefGoogle Scholar
  4. Cai XM, Barlow JF, Belcher SE (2008) Dispersion and transfer of passive scalars in and above street canyons—large-eddy simulations. Atmos Environ 42: 5885–5895CrossRefGoogle Scholar
  5. Caton F, Britter RE, Dalziel S (2003) Dispersion mechanism in a street canyon. Atmos Environ 37: 693–702CrossRefGoogle Scholar
  6. Chang CH, Meroney RN (2003) Concentration and flow distributions in urban street canyons: wind tunnel and computational data. J Wind Eng Ind Aerodyn 91: 1141–1154CrossRefGoogle Scholar
  7. Chan TL, Dong G, Leung CW, Cheung CS, Hung WT (2002) Validation of a two-dimensional pollutant dispersion model in an isolated street canyon. Atmos Environ 36: 861–872CrossRefGoogle Scholar
  8. DePaul FT, Sheih CM (1985) A tracer study of dispersion in an urban street canyon. Atmos Environ 19(4): 555–559CrossRefGoogle Scholar
  9. Hoydysh WG, Griffiths RA, Ogawa Y (1974) A scale model study of the dispersion of pollution in street canyons. APCA paper no. 74-157, 67th annual meeting of the air pollution control association, Denver, COGoogle Scholar
  10. Huang H, Akutsu Y, Arai M, Tamura M (2000) A two-dimensional air quality model in an urban street canyon: evaluation and sensitivity analysis. Atmos Environ 34: 689–698CrossRefGoogle Scholar
  11. Jeong SJ, Andrews MJ (2002) Application of the kε turbulence model to the high Reynolds number skimming flow field of an urban street canyon. Atmos Environ 36: 1137–1145CrossRefGoogle Scholar
  12. Johnson GT, Hunter LJ (1998) Urban wind flows: wind tunnel and numerical simulations—a preliminary comparison. Environ Model Softw 13: 279–286CrossRefGoogle Scholar
  13. Kastner-Klein P, Fedorovich E, Rotach MW (2001) A wind tunnel study of organised and turbulent air motions in urban street canyons. J Wind Eng Ind Aerodyn 89: 849–861CrossRefGoogle Scholar
  14. Kim JJ, Baik JJ (2001) Urban street-canyon flows with bottom heating. Atmos Environ 35: 3395–3404CrossRefGoogle Scholar
  15. Kovar-Panskus A, Moulinneuf L, Savory E, Abdelqari A, Sini JF, Rosant JM, Robins A, Toy N (2002) A wind tunnel investigation of the influence of solar-induced wall-heating on the flow regime within a simulated urban street canyon. Water Air Soil Pollut 2(5–6): 555–571Google Scholar
  16. Letzel MO, Krane M, Raasch S (2008) High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale. Atmos Environ 42: 8770–9784CrossRefGoogle Scholar
  17. Li XX (2008) Large-eddy simulation of wind flow and air pollutant transport inside urban street canyons of different aspect ratios. PhD thesis, The University of Hong Kong, 205 ppGoogle Scholar
  18. Li XX, Liu CH, Leung DYC (2005) Development of a kε model for the determination of air exchange rates for street canyons. Atmos Environ 39(38): 7285–7296CrossRefGoogle Scholar
  19. Li XX, Liu CH, Leung DYC, Lam KM (2006) Recent progress in CFD modelling of wind field and pollutant transport in street canyons. Atmos Environ 40(29): 5640–5658CrossRefGoogle Scholar
  20. Li XX, Leung DYC, Liu CH, Lam KM (2008a) Physical modeling of flow field inside urban street canyons. J Appl Meteorol Climatol 47(7): 2058–2067CrossRefGoogle Scholar
  21. Li XX, Liu CH, Leung DYC (2008b) Large-eddy simulation of flow and pollutant dispersion in urban street canyons with wall model. Boundary-Layer Meteorol 129(2): 249–268CrossRefGoogle Scholar
  22. Li XX, Liu CH, Leung DYC (2009) Numerical investigation of pollutant transport characteristics inside deep urban street canyons. Atmos Environ 43(15): 2410–2418CrossRefGoogle Scholar
  23. Li XX, Liu CH, Leung DYC (2010) Development of a parallel FEM LES with one-equation subgrid-scale model for incompressible flows. Int J Comput Fluid D 24(1): 37–49CrossRefGoogle Scholar
  24. Liu CH, Leung DYC (2006) Finite element solution to passive scalar transport behind line sources under neutral and unstable stratification. Int J Numer Methods Fluids 50(5): 623–648CrossRefGoogle Scholar
  25. Liu CH, Barth MC, Leung DYC (2004) Large-eddy simulation of flow and pollutant transport in street canyons of different building-height-to-street-width ratios. J Appl Meteorol 43: 1410–1424CrossRefGoogle Scholar
  26. Liu CH, Leung DYC, Barth MC (2005) On the prediction of air and pollutant exchange rates in street canyons of different aspect ratios using large-eddy simulation. Atmos Environ 39: 1567–1574Google Scholar
  27. Louka P, Belcher SE, Harrison RG (2000) Coupling between air flow in streets and the well-developed boundary layer aloft. Atmos Environ 34: 2613–2621CrossRefGoogle Scholar
  28. Meroney RN, Pavageau M, Rafadalis S, Schatzmann M (1996) Study of line source characteristics for 2D physical modelling of pollutant dispersion in street canyons. J Wind Eng Ind Aerodyn 62: 37–56CrossRefGoogle Scholar
  29. Moeng CH (1984) A large-eddy-simulation model for the study of planetary boundary-layer turbulence. J Atmos Sci 4(13): 2052–2062CrossRefGoogle Scholar
  30. Niachou K, Livada L, Santamouris M (2008) Experimental study of temperature and airflow distribution inside an urban street canyon during hot summer weather conditions—part I: air and surface temperatures. Build Environ 43: 1383–1392CrossRefGoogle Scholar
  31. Oke T (1988) Street design and urban canopy layer climate. Energy Build 11: 103–113CrossRefGoogle Scholar
  32. Pavageau M, Schatzmann M (1999) Wind tunnel measurements of concentration fluctuations in an urban street canyon. Atmos Environ 33: 3961–3971CrossRefGoogle Scholar
  33. Qin Y, Kot SC (1993) Dispersion of vehicular emission in street canyons, Guangzhou city, South China (PRC). Atmos Environ 27B: 283–291Google Scholar
  34. Saiki EM, Moeng CH, Sullivan PP (2000) Large-eddy simulation of the stably stratified planetary boundary layer. Boundary-Layer Meteorol 95: 1–30CrossRefGoogle Scholar
  35. Sasaki H, Miyakoshi H, Ito H (1989) Water flow visualization studies on convective diffusion of layering and leakage in rectangular cavities aside a main flow way. In: Papers on The society of heating, air-conditioning and sanitary engineers of Japan, vol 39, pp 121–131Google Scholar
  36. Sini JF, Anquetin S, Mestayer PG (1996) Pollutant dispersion and thermal effects in urban street canyons. Atmos Environ 30: 2659–2677CrossRefGoogle Scholar
  37. Uehara K, Murakami S, Oikawa S, Wakamatsu S (2000) Wind tunnel experiments on how thermal stratification affects flow in and above urban street canyons. Atmos Environ 34: 1553–1562CrossRefGoogle Scholar
  38. Xie S, Zhang Y, Qi L, Tang X (2003) Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos Environ 37: 3213–3224CrossRefGoogle Scholar
  39. Xie X, Liu CH, Leung DYC, Leung MKH (2006) Characteristics of air exchange in a street canyon with ground heating. Atmos Environ 40(33): 6396–6409CrossRefGoogle Scholar
  40. Xie X, Liu CH, Leung DYC (2007) Impact of building facades and ground heating on wind flow and pollutant transport in street canyons. Atmos Environ 41: 9030–9049CrossRefGoogle Scholar
  41. Yi L, Lim H (2004) Comparison of convective environments in tropical and extratropical atmospheres with 1989–2002 radiosonde data. In: Proceedings of 26th conference on hurricanes and tropical meteorology, Miami, FL, USA, 3–7 May 2004Google Scholar

Copyright information

© The Author(s) 2010

Open AccessThis is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/2.0), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Authors and Affiliations

  • Xian-Xiang Li
    • 1
    Email author
  • Rex E. Britter
    • 2
  • Tieh Yong Koh
    • 3
  • Leslie K. Norford
    • 4
  • Chun-Ho Liu
    • 5
  • Dara Entekhabi
    • 6
  • Dennis Y. C. Leung
    • 5
  1. 1.CENSAMSingapore-MIT Alliance for Research and TechnologySingaporeSingapore
  2. 2.Department of Urban Studies and PlanningMassachusetts Institute of TechnologyCambridgeUSA
  3. 3.School of Physical and Mathematical SciencesNanyang Technological UniversitySingaporeSingapore
  4. 4.Department of ArchitectureMassachusetts Institute of TechnologyCambridgeUSA
  5. 5.Department of Mechanical EngineeringThe University of Hong KongHong KongChina
  6. 6.Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeUSA

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