Diffusion near buildings as determined from atmospheric tracer experiments. Technical report

Sagendorf, J. F.; Ricks, N.R.; Start, G.E.; Dickson, C. R.

doi:10.2172/6214193

Cited by 3 publications

(3 citation statements)

References 2 publications

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“…Over the years, many tracer field studies have been conducted investigating dispersion in individual street canyons (e.g., Huang et al 2000;DePaul and Sheih 1985), around individual buildings (e.g., Oikawa and Meng 1997;Jones and Griffiths 1984;Ogawa and Oikawa 1982), through multibuilding and industrial complexes (e.g., Thistle et al 1995;Guenther et al 1990;Sagendorf et al 1980), and through urban areas (e.g., Cooke et al 2000;McElroy 1997;Allwine et al 1992;Gryning and Lyck 1984). Additionally, numerous wind tunnel and laboratory studies have been conducted investigating flows and diffusion around idealized structures, individual buildings, and industrial complexes (e.g., Zhang et al 1996;Higson et al 1994;Mirzai et al 1994;Ramsdell 1990;Huber 1989;Hosker 1987;Hosker 1984;Huber and Snyder 1982;Allwine et al 1980;Abbey 1976).…”

mentioning

confidence: 99%

Overview of URBAN 2000: A Multiscale Field Study of Dispersion through an Urban Environment

Allwine¹,

Shinn²,

Streit³

et al. 2002

Bull. Amer. Meteor. Soc.

198

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confidence: 99%

Overview of URBAN 2000: A Multiscale Field Study of Dispersion through an Urban Environment

Allwine¹,

Shinn²,

Streit³

et al. 2002

Bull. Amer. Meteor. Soc.

198

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“…Sagendorf et al 7 conducted a series of tests involving the release of a tracer gas and measurement of its concentration near two large nuclear facilities. The results from these tests were in good agreement with the predictions of Wilson's model, and showed that the appropriate wind speed, U, for calculating dilution is the undisturbed flow speed upwind of the building.…”

Section: Models Of the Form: D Mln = B X ^ ( £-Vmentioning

confidence: 99%

Review and Evaluation of Models Estimating the Minimum Atmospheric Dilution of Gases Exhausted Near Buildings

Georgakis

Smith

Goodfellow³

et al. 1995

Journal of the Air & Waste Management Association

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In this study, eleven mathematical models estimating the minimum possible atmospheric dilution of rooftop exhaust gases around buildings are evaluated and reviewed using data obtained from 72 full-scale tracer tests at two buildings. Quantities measured were the stack height, stack-tointake distance, stack diameter, wind speed and direction, exhaust flux, and the stack-to-intake dilution. These models are all based on wind-tunnel simulations and are designed to account for a worst-case scenario so that they can be used to provide a conservative safeguard for design of new stacks or for modification purposes. Although none of the models gave outstanding performance relative to the others, Halitsky's model, derived from the prism tests and Clinical Center data incorporating the exhaust momentum ratio, gave particularly good predictions. Further, all models led to very conservative estimates of the dilution in the case of gases exhausted close to a receptor, suggesting that the models reviewed here should not be used in such cases. IMPLICATIONSThis study examines the selected mathematical models which determine the dilution ratio of a contaminant concentration for an exhaust stack discharge compared to the contaminant concentration at the building intakes. The literature contains a wide range of semi-empirical models which have been developed based on wind tunnel studies. The models are worst-case scenarios and can be used as safeguards for the design modification of ventilation facilities. The present research is of significance because it represents a detailed field measurement program at two full-scale laboratory buildings to determine the dilution of exhaust gases between the stack and the intake. The results provide guidelines for policy makers and designers of industrial and laboratory facilities to use in selecting realistic models to determine appropriate separation distances from the stack discharge and intake for the building ventilation systems. INTRODUCTIONThe effect of buildings on pollutant dispersion is often an important aspect of air quality impact analyses. A plume that is entrained in the flow region around a building can result in concentration fields that are considerably different from those measured in the absence of the building, and which may significantly affect building occupants and equipment operation by contaminating the fresh air intakes.The complexity of these fields is so great that the use of conventional diffusion formulae for their quantitative description often produces misleading results. Such formulae contain the implicit assumptions that the flow field has straight parallel streamlines, modest velocity gradients, and uniform turbulence distributions. Although this is typical of flow over uniformly rough ground, flow around buildings is characterized by curved streamlines, sharp velocity discontinuities, and highly non-homogeneous turbulence. All of these factors disperse effluents in a complicated manner uniquely related to source location and building configuration.A...

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“…46 More recent studies include Huntington Canyon, 67 Clinch River, 68 low wind inversion conditions, 69 Garfield smelter, 70 Rancho Seca, 71 and additional studies in the vicinity of a reactor building. 72 Many urban studies also contributed to the knowledge of meteorological influences on pollutants. An early comprehensive study conducted mostly before World War II in Leicester, England was reported by the Department of Scientific and Industrial Research.…”

Section: Measured Concentrationsmentioning

confidence: 99%

A Critical Review

Turner¹

1979

Journal of the Air Pollution Control Association

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There are many requirements for dispersion models in the Clean Air Act Amendments of 1977 including prevention of significant deterioration, air quality maintenance plans, and new source permits. The historical perspective of dispersion modeling includes both theoretical and practical developments, rural and urban field studies including tracer studies, plume rise, and urban modeling. Photochemical modeling includes both grid point and trajectory models. Off-the-shelf models include level terrain models for elevated point sources, urban point and area sources, and transportation sources; and complex terrain models for point sources. Models are needed for photochemical pollutants, sulfates, and nitrates; they should treat long range transport, topographic effects, build-up of urban concentrations, and aerodynamic downwash. Emphasis is placed herein upon proper interpretation of vertical temperature structure measurements, and the difficulties in determining the magnitude and locations of the highest and second highest concentrations in a year. Modeling improvements can be expected with representative on-site measurements of input parameters, and improved dispersion parameter schemes which must be verified with appropriate field investigations. Terms related to model evaluation are defined. A primary source of error, in comparing model estimates with monitored air quality, is not including the actual change of wind direction with height which determines elevated plume position. Measures for model evaluation will differ depending upon model use. The paper concludes asking for 1) encouragement of model development, 2) improvement of model inputs through on-site measurements, and 3) detailed field investigations.Mr. Turner is presently on assignment from the National

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Diffusion near buildings as determined from atmospheric tracer experiments. Technical report

Cited by 3 publications

References 2 publications

Overview of URBAN 2000: A Multiscale Field Study of Dispersion through an Urban Environment

Overview of URBAN 2000: A Multiscale Field Study of Dispersion through an Urban Environment

Review and Evaluation of Models Estimating the Minimum Atmospheric Dilution of Gases Exhausted Near Buildings

A Critical Review

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