The influence of street architecture on flow and dispersion in street canyons

SummaryThe paper presents an overview of the influence of street architecture on the wind and turbulence patterns in street canyons and discusses the effects on local air quality. The findings of recent experimental and numerical studies are summarized and wind-tunnel data sets are presented that illustrate the flow-field variability. It is shown that small-scale features of the street architecture play an important role. The formation of a vortex inside the street canyon is affected by the roof configuration. In shorter street canyons, the flow component along the street becomes important for pollutant transport. These results are of importance for urban air quality modeling in particular when dealing with pollution problems caused by road traffic. Furthermore, the findings should be taken into account in fast response models that are used to assess critical areas in the case of accidental or non-accidental releases of hazardous material in urban areas.

[1]  G. T. Johnson,et al.  Modelling air flow regimes in urban canyons , 1990 .

[2]  G. T. Johnson,et al.  A numerical study of dispersion of passive scalars in city canyons , 1995 .

[3]  Walter F. Dabberdt,et al.  Street canyon dispersion: Sensitivity to block shape and entrainment , 1991 .

[4]  Mathias W. Rotach,et al.  Mean Flow and Turbulence Characteristics in an Urban Roughness Sublayer , 2004 .

[5]  P. Louka,et al.  Measurements of Traffic-Induced Turbulence within a Street Canyon during the Nantes'99 Experiment , 2002 .

[6]  S. Hanna,et al.  Air quality model performance evaluation , 2004 .

[7]  Mathias W. Rotach,et al.  Turbulence close to a rough urban surface part I: Reynolds stress , 1993 .

[8]  Ian P. Castro,et al.  Near Wall Flow over Urban-like Roughness , 2002 .

[9]  Mathias W. Rotach,et al.  A wind tunnel study of organised and turbulent air motions in urban street canyons , 2001 .

[10]  G. T. Johnson,et al.  An investigation of three-dimensional characteristics of flow regimes within the urban canyon , 1992 .

[11]  R. G. Harrison,et al.  Coupling between air flow in streets and the well-developed boundary layer aloft , 2000 .

[12]  Rainald Löhner,et al.  Comparisons of model simulations with observations of mean flow and turbulence within simple obstacle arrays , 2002 .

[13]  K. Pericleous,et al.  Modelling air quality in street canyons : a review , 2003 .

[14]  Matthias Ketzel,et al.  Intercomparison of Numerical Urban Dispersion Models – Part I: Street Canyon and Single Building Configurations , 2002 .

[15]  G. Vachon,et al.  MEASUREMENTS OF DYNAMIC AND THERMAL FIELD IN A STREET CANYON. URBCAP NANTES'99 , 1999 .

[16]  Matthias Ketzel,et al.  Intercomparison of Numerical Urban Dispersion Models – Part II: Street Canyon in Hannover, Germany , 2001 .

[17]  Mathias W. Rotach,et al.  Turbulence close to a rough urban surface part II: Variances and gradients , 1993 .

[18]  Stylianos Rafailidis,et al.  Influence of Building Areal Density and Roof Shape on the Wind Characteristics Above a Town , 1997 .

[19]  Rex Britter,et al.  Dispersion mechanisms in a street canyon , 2003 .

[20]  Nicolas Moussiopoulos,et al.  The microscale model MIMO: development and assessment , 2000 .

[21]  Michael Schatzmann,et al.  Study of line source characteristics for 2-D physical modelling of pollutant dispersion in street canyons , 1996 .

[22]  R. Britter,et al.  FLOW AND DISPERSION IN URBAN AREAS , 2003 .

[23]  Erich J. Plate,et al.  Wind-tunnel study of concentration fields in street canyons , 1999 .

[24]  A. Chan,et al.  Strategic guidelines for street canyon geometry to achieve sustainable street air quality , 2001 .

[25]  Sandrine Anquetin,et al.  Pollutant dispersion and thermal effects in urban street canyons , 1996 .

[26]  J.-F. Sini,et al.  Thermal Effects on the Airflow in a Street Canyon – Nantes'99 Experimental Results and Model Simulations , 2002 .

[27]  Michael Schatzmann,et al.  Validation and application of obstacle-resolving urban dispersion models , 2002 .

[28]  M. J. Brown,et al.  Mean flow and turbulence measurements around a 2-D array of buildings in a wind tunnel , 2000 .

[29]  J.-F. Sini,et al.  Influence of Geometry on the Mean Flow within Urban Street Canyons – A Comparison of Wind Tunnel Experiments and Numerical Simulations , 2002 .

[30]  Jong-Jin Baik,et al.  Effects of inflow turbulence intensity on flow and pollutant dispersion in an urban street canyon , 2003 .

[31]  M. Rotach.  Profiles of turbulence statistics in and above an urban street canyon , 1995 .

[32]  F. T. Depaul,et al.  Measurements of wind velocities in a street canyon , 1986 .

[33]  C. Ratti,et al.  Analysis of 3-D Urban Databases with Respect to Pollution Dispersion for a Number of European and American Cities , 2001 .