Flow and Turbulence in an Urban Canyon

Abstract A better understanding of the interaction between the built environment and the atmosphere is required to more effectively manage urban airsheds. This paper reports an analysis of data from an atmospheric measurement campaign in Oklahoma City, Oklahoma, during the summer of 2003 that shows wind flow patterns, turbulence, and thermal effects in the downtown area. Experimental measurements within a street canyon yielded airflow patterns, stability conditions, and turbulence properties as a function of the incoming wind direction and time of the day. Air and surface temperatures at two different sites, one within the downtown urban canyon and the other in a nearby park, were measured. A study of the stability conditions within the urban canyon during the campaign indicates that dynamically stable conditions did not occur within the canyon. This provides evidence that the built environment can strongly influence the thermal characteristics in cities. Mean flow patterns close to the street level are a...

[1]  J. Counehan,et al.  Wind tunnel determination of the roughness length as a function of the fetch and the roughness density of three-dimensional roughness elements , 1971 .

[2]  R. Macdonald,et al.  Modelling The Mean Velocity Profile In The Urban Canopy Layer , 2000 .

[3]  W. J. Beranek,et al.  GENERAL RULES FOR THE DETERMINATION OF WIND ENVIRONMENT , 1980 .

[4]  B. E. Lee,et al.  A wind tunnel study of the mean pressure forces acting on large groups of low-rise buildings , 1980 .

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

[6]  T. Oke.  Street design and urban canopy layer climate , 1988 .

[7]  S. Nicholson,et al.  A pollution model for street-level air. , 1975, Atmospheric environment.

[8]  Jong-Jin Baik,et al.  A Numerical Study of Thermal Effects on Flow and Pollutant Dispersion in Urban Street Canyons , 1999 .

[9]  Robert L. Lee,et al.  Flow around a Complex Building: Comparisons between Experiments and a Reynolds-Averaged Navier¿Stokes Approach , 2004 .

[10]  Rex Britter,et al.  Velocity measurements and order of magnitude estimates of the flow between two buildings in a simulated atmospheric boundary layer , 1979 .

[11]  R. Berkowicz,et al.  The influence of street architecture on flow and dispersion in street canyons , 2004 .

[12]  Jong-Jin Baik,et al.  Urban street-canyon flows with bottom heating , 2001 .

[13]  Jason Ching,et al.  Simulation of Meteorological Fields Within and Above Urban and Rural Canopies with a Mesoscale Model , 2004 .

[14]  H. Khalsa,et al.  Street canyon flow patterns in a horizontal plane : measurements from the Joint URBAN 2003 field experiment , 2004 .

[15]  M. J. Brown,et al.  Properties of the Wind Field within the Oklahoma City Park Avenue Street Canyon. Part II: Spectra, Cospectra, and Quadrant Analyses , 2007 .

[16]  Hosker.  Methods for estimating wake flow and effluent dispersion near simple block-like buildings. Technical memo , 1981 .

[17]  Lionel Soulhac.  Modélisation de la dispersion atmosphérique à l'intérieur de la canopée urbaine , 2000 .

[18]  R. Britter,et al.  Spatially averaged flow within obstacle arrays , 2003 .

[19]  Michael R. Raupach,et al.  A wind-tunnel study of turbulent flow close to regularly arrayed rough surfaces , 1980 .

[20]  H. Fernando,et al.  Virtual towers using coherent doppler lidar during the Joint Urban 2003 dispersion experiment , 2006 .

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

[22]  E. Pardyjak,et al.  Observations of the Effects of Atmospheric Stability on Turbulence Statistics Deep within an Urban Street Canyon , 2007 .

[23]  P. Klein,et al.  Flow Variability in a North American Downtown Street Canyon , 2007 .

[24]  P. S. Jackson,et al.  Wakes behind two-dimensional surface obstacles in turbulent boundary layers , 1974, Journal of Fluid Mechanics.

[25]  A. Chan,et al.  Strategic guidelines for street canyon geometry to achieve sustainable street air quality—part II: multiple canopies and canyons , 2003 .

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

[27]  Patricia A. O'Rourke,et al.  Simulating the causal elements of urban heat islands , 1980 .

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

[29]  Huang Zhen,et al.  The impact of urban street layout on local atmospheric environment , 2006 .

[30]  B. L. Clarkson.  Formulas for natural frequency and mode shape 1979: R. D. Blevins. New York: Van Nostrand Reinhold, 492 pp; price $32.50 , 1981 .

[31]  M. Parlange,et al.  Modeling flow around bluff bodies and predicting urban dispersion using large eddy simulation. , 2006, Environmental science & technology.

[32]  J. Hunt,et al.  Kinematical studies of the flows around free or surface-mounted obstacles; applying topology to flow visualization , 1978, Journal of Fluid Mechanics.

[33]  Brent C. Hedquist,et al.  Flow, turbulence, and pollutant dispersion in urban atmospheresa) , 2010 .

[34]  Sang Jin Jeong,et al.  Application of the k–ε turbulence model to the high Reynolds number skimming flow field of an urban street canyon , 2002 .

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

[36]  K. J. Allwine,et al.  OVERVIEW OF URBAN 2000 A Multiscale Field Study of Dispersion through an Urban Environment , 2002 .

[37]  A. D. Penwarden,et al.  Wind environment around buildings , 1975 .

[38]  Rex Britter,et al.  Estimates of building surface concentrations from nearby point sources , 1982 .

[39]  Matthew A. Nelson,et al.  Properties of the Wind Field within the Oklahoma City Park Avenue Street Canyon. Part I. Mean Flow and Turbulence Statistics , 2007 .

[40]  J. Cermák,et al.  Wind-tunnel measurements in the wakes of structures , 1977 .

[41]  H. Fernando.  Fluid Dynamics of Urban Atmospheres in Complex Terrain , 2010 .

[42]  Matthias Roth,et al.  Review of atmospheric turbulence over cities , 2007 .

[43]  Yasushi Sakakibara,et al.  A numerical study of the effect of urban geometry upon the surface energy budget , 1996 .

[44]  Hansheng Pan,et al.  Lateral channeling within rectangular arrays of cubical obstacles , 2010 .

[45]  S. Grossman-Clarke,et al.  Urban Fluid Mechanics: Air Circulation and Contaminant Dispersion in Cities , 2001 .

[46]  M. Tutar,et al.  Large eddy simulation of wind flow around parallel buildings with varying configurations , 2002 .

[47]  Jong-Jin Baik,et al.  A CFD Model for Simulating Urban Flow and Dispersion , 2003 .

[48]  W. B. Johnson,et al.  An urban diffusion simulation model for carbon monoxide. , 1973, Journal of the Air Pollution Control Association.

[49]  H. Park,et al.  PARAMETERIZATION OF THE POLLUTANT TRANSPORT AND DISPERSION IN URBAN STREET CANYONS , 1994 .