Environmental Fluid Mechanics

, Volume 16, Issue 2, pp 313–334 | Cite as

Revisiting the flow regimes for urban street canyons using the numerical Green’s function

Original Article

Abstract

Vortex interactions within a two-dimensional street canyon are analysed using the numerical Green’s function. On account of the inhomogeneity of the domain, vortex interactions are asymmetric: the influence of a street-level vorticity source on the roof-level shear layer differs from that of the latter on the street level. Consequently the magnitudes of the induced vertical velocities are maximised at different aspect ratios. It is argued that the transition from isolated roughness to wake interference is related to the onset of strong long-range interactions while the transition from wake interference to skimming flow is related to the weakening of these interactions. The Green’s function analysis is verified using three-dimensional large-eddy simulations.

Keywords

Aspect ratio Green’s function Large-eddy simulation Urban street canyon Vortex dynamics 

References

  1. 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. 2.
    Chung T, Liu CH (2013) On the mechanism of air pollutant removal in two-dimensional idealized street canyons: a large-eddy simulation approach. Bound-Layer Meteorol 148:241–253CrossRefGoogle Scholar
  3. 3.
    Cui Z, Cai X, Baker CJ (2004) Large-eddy simulation of turbulent flow in a street canyon. Q J R Meteorol Soc 130:1373–1394. doi:10.1256/qj.02.150 CrossRefGoogle Scholar
  4. 4.
    Deardorff J (1980) Stratocumulus-capped mixed layers derived from a three-dimensional model. Bound-Layer Meteorol 18(4):495–527. doi:10.1007/BF00119502 CrossRefGoogle Scholar
  5. 5.
    Fernando HJS, Lee S, Anderson J, Princevac M, Pardyjak E, Grossman-Clarke S (2001) Urban fluid mechanics: air circulation and contaminant dispersion in cities. Environ Fluid Mech 1:107–164CrossRefGoogle Scholar
  6. 6.
    Holzer M (1999) Analysis of passive tracer transport as modeled by an atmospheric general circulation model. J Clim 12:1659–1684CrossRefGoogle Scholar
  7. 7.
    Hunt J, Durbin P (1999) Perturbed vortical layers and shear sheltering. Fluid Dyn Res 24:375–404. doi:10.1016/S0169-5983(99)00009-X CrossRefGoogle Scholar
  8. 8.
    Hunter L, Johnson G, Watson I (1992) An investigation of three-dimensional characteristics of flow regimes within the urban canyon. Atmos Environ 26:425–432. doi:10.1016/0957-1272(92)90049-X CrossRefGoogle Scholar
  9. 9.
    Hunter L, Watson I, Johnson G (1990) Modelling air flow regimes in urban canyons. Energy Build 15:315–324. doi:10.1016/0378-7788(90)90004-3 CrossRefGoogle Scholar
  10. 10.
    Kwak KH, Baik JJ (2014) Diurnal variation of nox and ozone exchange between a street canyon and the overlying air. Atmos Environ 86:120–128CrossRefGoogle Scholar
  11. 11.
    Lee I, Park H (1994) Parameterization of the pollutant transport and dispersion in urban street canyons. Atmos Environ 28:2343–2349CrossRefGoogle Scholar
  12. 12.
    Letzel MO, Krane M, Raasch S (2008) High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale. Atmos Environ 42:8770–8784. doi:10.1016/j.atmosenv.2008.08.001 CrossRefGoogle Scholar
  13. 13.
    Li X, Liu CH, Leung DYC, Lam K (2006) Recent progress in CFD modelling of wind field and pollutant transport in street canyons. Atmos Environ 40:5640–5658. doi:10.1016/j.atmosenv.2006.04.055 CrossRefGoogle Scholar
  14. 14.
    Lo KW, Ngan K (2015) Predictability of turbulent flow in street canyons. Bound-Layer Meteorol (in press). doi:10.1007/s10546-015-0014-z
  15. 15.
    Madalozzo D, Braun A, Awruch A, Morsch I (2014) Numerical simulation of pollutant dispersion in street canyons: geometric and thermal effects. Appl Math Model 38:5883–5909. doi:10.1016/j.apm.2014.04.041 CrossRefGoogle Scholar
  16. 16.
    Magnusson S, Dallman A, Entekhabi D, Britter R, Fernando HJS, Norford L (2014) On thermally forced flows in urban street canyons. Environ Fluid Mech 14:1427–1441CrossRefGoogle Scholar
  17. 17.
    Ngan K, Straub DN, Bartello P (2005) Aspect ratio effects in quasi-two-dimensional turbulence. Phys Fluids 17, 125,102-1-125,102–17Google Scholar
  18. 18.
    Oke TR (1988) Street design and urban canopy layer climate. Energy Build 11:103–113. doi:10.1016/0378-7788(88)90026-6 CrossRefGoogle Scholar
  19. 19.
    OpenFOAM: OpenFOAM: the open source CFD toolbox (2014). URL: http://www.openfoam.org
  20. 20.
    Park SB, Baik JJ (2013) A large-eddy simulation study of thermal effects on turbulence coherent structures in and above a building array. J Appl Meteorol Climatol 52:1348–1365. doi:10.1175/JAMC-D-12-0162.1 CrossRefGoogle Scholar
  21. 21.
    Pope SB (2000) Turbulent flows. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  22. 22.
    Raasch S, Schröter M (2001) PALM—a large-eddy simulation model performing on massively parallel computers. Meteorol Z 10:363–372CrossRefGoogle Scholar
  23. 23.
    Saffman PG (1992) Vortex dynamics. Cambridge University Press, CambridgeGoogle Scholar
  24. 24.
    Sini JF, Anquetin S, Mestayer PG (1996) Pollutant dispersion and thermal effects in urban street canyons. Atmos Environ 30:2659–2677. doi:10.1016/1352-2310(95)00321-5 CrossRefGoogle Scholar
  25. 25.
    Vardoulakis S, Fisher BE, Pericleous K, Gonzalez-Flesca N (2003) Modelling air quality in street canyons: a review. Atmos Environ 37:155–182. doi:10.1016/S1352-2310(02)00857-9 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  1. 1.Guy Carpenter Asia-Pacific Climate Impact Centre, School of Energy and EnvironmentCity University of Hong KongKowloonHong Kong
  2. 2.School of Energy and EnvironmentCity University of Hong KongKowloonHong Kong

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