Boundary-Layer Meteorology

, Volume 142, Issue 2, pp 207–222 | Cite as

Large-Eddy Simulation of Coherent Flow Structures within a Cubical Canopy

  • Atsushi Inagaki
  • Marieta Cristina L. Castillo
  • Yoshimi Yamashita
  • Manabu Kanda
  • Hiroshi Takimoto


Instantaneous flow structures “within” a cubical canopy are investigated via large-eddy simulation. The main topics of interest are, (1) large-scale coherent flow structures within a cubical canopy, (2) how the structures are coupled with the turbulent organized structures (TOS) above them, and (3) the classification and quantification of representative instantaneous flow patterns within a street canyon in relation to the coherent structures. We use a large numerical domain (2,560 m × 2,560 m × 1,710 m) with a fine spatial resolution (2.5 m), thereby simulating a complete daytime atmospheric boundary layer (ABL), as well as explicitly resolving a regular array of cubes (40 m in height) at the surface. A typical urban ABL is numerically modelled. In this situation, the constant heat supply from roof and floor surfaces sustains a convective mixed layer as a whole, but strong wind shear near the canopy top maintains the surface layer nearly neutral. The results reveal large coherent structures in both the velocity and temperature fields “within” the canopy layer. These structures are much larger than the cubes, and their shapes and locations are shown to be closely related to the TOS above them. We classify the instantaneous flow patterns in a cavity, specifically focusing on two characteristic flow patterns: flushing and cavity-eddy events. Flushing indicates a strong upward motion, while a cavity eddy is characterized by a dominant vortical motion within a single cavity. Flushing is clearly correlated with the TOS above, occurring frequently beneath low-momentum streaks. The instantaneous momentum and heat transport within and above a cavity due to flushing and cavity-eddy events are also quantified.


Cavity eddy Cubical canopy Flushing Instantaneous flow regime Large-eddy simulation Turbulent organized structure 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  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. Barlow JF, Harman IN, Belcher SE (2004) Scalar fluxes from urban street canyon. Part I: laboratory simulation. Boundary-Layer Meteorol 113: 369–385CrossRefGoogle Scholar
  3. Barlow JF, Dobre A, Smalley RJ, Arnold SJ, Tomlin AS, Belcher SE (2009) Referencing of street-level flows measured during the DAPPLE 2004 campaign. Atmos Environ 43: 5536–5544CrossRefGoogle Scholar
  4. Briscolini M, Santangelo P (1989) Development of the mask method for incompressible unsteady flows. J Comput Phys 84: 57–75CrossRefGoogle Scholar
  5. Castillo MCL, Inagaki A, Kanda M (2011) Inner and outer turbulence within the inertial sublayer of a near-neutral atmospheric flow over an urban-like surface. Boundary-Layer Meteorol 140: 453–469CrossRefGoogle Scholar
  6. Cheng H, Castro IP (2002) Near wall flow over urban-like roughness. Boundary-Layer Meteorol 104: 229–259CrossRefGoogle Scholar
  7. Christen A, Gorsel E, Vogt R (2007) Coherent structures in urban roughness sublayer turbulence. Int J Climatol 27: 1955–1968CrossRefGoogle Scholar
  8. Coceal O, Dobre A, Thomas TG, Belcher SE (2007) Structure of turbulent flow over regular arrays of cubical roughness. J Fluid Mech 589: 375–409CrossRefGoogle Scholar
  9. Dobre A, Arnold SJ, Smalley RJ, Boddy JWD, Barlow JF, Tomlin AS, Belcher SE (2005) Flow field measurements in the proximity of an urban intersection in London, UK. Atmos Environ 39: 4647–4657CrossRefGoogle Scholar
  10. Drobinski P, Carlotti P, Newsom RK, Banta RM, Foster RC, Redelsperger JL (2004) The structure of the near-neutral atmospheric surface layer. J Atmos Sci 61: 699–714CrossRefGoogle Scholar
  11. Eliasson I, Offerle B, Grimmond CSB, Lindqvist S (2006) Wind fields and turbulence statistics in an urban street canyon. Atmos Environ 40: 1–16CrossRefGoogle Scholar
  12. Grimmond CSB, Oke TR (1999) Aerodynamic properties of urban areas derived from analysis of surface form. J Appl Meteorol 38: 1262–1292CrossRefGoogle Scholar
  13. Hunt JCR, Morrison JF (2000) Eddy structure in turbulent boundary layers. Eur J Mech B Fluids 19: 673–694CrossRefGoogle Scholar
  14. Inagaki A, Kanda M (2008) Turbulent flow similarity over an array of cubes in near-neutrally stratified atmospheric flow. J Fluid Mech 615: 101–120CrossRefGoogle Scholar
  15. Inagaki A, Kanda M (2010) Organized structure of active turbulence developed over an array of cube within the logarithmic layer of atmospheric flow. Boundary-Layer Meteorol 135: 209–228CrossRefGoogle Scholar
  16. Inagaki A, Letzel MO, Raasch S, Kanda M (2006) Impact of surface heterogeneity on energy imbalance: a study using LES. J Meteorol Soc Jpn 84: 187–198CrossRefGoogle Scholar
  17. Kanda M (2006) Large eddy simulations on the effects of surface geometry of building arrays on turbulent organized structures. Boundary-Layer Meteorol 118: 151–168CrossRefGoogle Scholar
  18. Kanda M, Moriwaki R, Kasamatsu F (2004a) Large eddy simulation of turbulent organized structure within and above explicitly resolved cubic arrays. Boundary-Layer Meteorol 112: 343–368CrossRefGoogle Scholar
  19. Kanda M, Inagaki A, Letzel MO, Raasch S, Watanabe T (2004b) LES study of the energy imbalance problem with eddy covariance fluxes. Boundary-Layer Meteorol 110: 381–404CrossRefGoogle Scholar
  20. Kawai T, Kanda M, Narita K, Hagishima A (2007) Validation of a numerical model for urban energy-exchange using outdoor scale-model measurements. Int J Climatorol 27: 1931–1942CrossRefGoogle Scholar
  21. Kim JJ, Baik JJ (2004) A numerical study of the effects of ambient wind direction on flow and dispersion in urban street canyons using the RNG k–\({\varepsilon}\) turbulence model. Atmos Environ 38(19): 3039–3048CrossRefGoogle Scholar
  22. Letzel MO (2007) High resolution large-eddy simulation of turbulent flow around buildings. Ph.D. thesis, Gottfried Wilhelm Leibniz Universität HannoverGoogle Scholar
  23. Letzel MO, Krane M, Raasch S (2008) High resolution urban large-eddy simulation studies from street canyon to neighborhood scale. Atmos Environ 42(38): 8770–8784CrossRefGoogle Scholar
  24. Louka P, Vachon G, Sini JF, Mestayer PG, Rosant JM (2002) Thermal effects on the airflow in a street canyon—Nantes’99 experimental results and model simulations. Water Air Soil Pollut 2(5–6): 351–364Google Scholar
  25. MacDonald RW (2000) Modelling the mean velocity profile in the urban canopy layer. Boundary-Layer Meteorol 97: 25–45CrossRefGoogle Scholar
  26. MacDonald RW, Griffiths RF, Hall DJ (1998) An improved method for the estimation of surface roughness of obstacle array. Atmos Environ 32(11): 1857–1864CrossRefGoogle Scholar
  27. Marusic I, McKeon BJ, Monkewitz PA, Nagib HM, Smits AJ, Sreenivasan KR (2010) Wall-bounded turbulent flows at high Reynolds numbers: recent advances and key issues. Phys Fluids 22: 065103CrossRefGoogle Scholar
  28. Michioka T, Sato A, Takimoto H, Kanda M (2011) Large-eddy simulation for the mechanism of pollutant removal from a two-dimensional street canyon. Boundary-Layer Meteorol 138: 195–213CrossRefGoogle Scholar
  29. Moriwaki R, Kanda M (2006) Local and global similarity in turbulent transfer of heat, water vapour, and CO2 in the dynamic convective sublayer over a suburban area. Boundary-Layer Meteorol 120: 163–179CrossRefGoogle Scholar
  30. Narita K (2007) Experimental study of the transfer velocity for urban surfaces with a water evaporation method. Boundary-Layer Meteorol 122: 293–320CrossRefGoogle Scholar
  31. Oikawa S, Meng Y (1995) Turbulence characteristics and organized motion in a suburban roughness sublayer. Boundary-Layer Meteorol 74: 289–312CrossRefGoogle Scholar
  32. Oke TR (1987) Boundary layer climates, 2nd edn. Routledge, London, p 435Google Scholar
  33. Raasch S, Harbusch G (2001) Analysis of secondary circulations and their effects caused by small-scale surface inhomogeneities using large-eddy simulation. Boundary-Layer Meteorol 101: 31–59CrossRefGoogle Scholar
  34. Raasch S, Schröter M (2001) PALM—A large-eddy simulation model performing on massively parallel computers. Meteorol Z 10: 363–372CrossRefGoogle Scholar
  35. Raupach MR, Shaw RH (1982) Averaging procedures for flow within vegetation canopies. Boundary-Layer Meteorol 22: 79–90CrossRefGoogle Scholar
  36. Raupach MR, Finnigan JJ, Brunet Y (1996) Coherent eddies and turbulence in vegetation canopies: the mixing-layer analogy. Boundary-Layer Meteorol 78: 351–382CrossRefGoogle Scholar
  37. Roth M (2000) Review of atmospheric turbulence over cities. Q J Roy Meteorol Soc 126: 941–990CrossRefGoogle Scholar
  38. Takimoto H, Sato A, Barlow JF, Moriwaki R, Onomura S, Kanda M (2011) PIV measurements of turbulent flow within an outdoor urban scale model and flushing motions in urban canopy layers. Boundary-Layer Meteorol 140: 295–314CrossRefGoogle Scholar
  39. 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
  40. Voogt JA, Oke TR (1997) Complete urban surface temperatures. J Appl Meteorol 36: 1117–1132CrossRefGoogle Scholar
  41. Watanabe T (2004) Large-eddy simulation of coherent turbulence structures associated with scalar ramps over plant canopies. Boundary-Layer Meteorol 112: 307–341CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Atsushi Inagaki
    • 1
  • Marieta Cristina L. Castillo
    • 1
  • Yoshimi Yamashita
    • 1
  • Manabu Kanda
    • 1
  • Hiroshi Takimoto
    • 1
  1. 1.Department of International Development EngineeringTokyo Institute of TechnologyTokyoJapan

Personalised recommendations