Civil Engineering Reports
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From 1947 to 1996, the Colorado State University Department of Civil Engineering issued reprints of engineering papers, bulletins, and documents as the series Civil Engineering Reports. University faculty and students authored most reports, and the department assigned report numbers in order of acquisition for each year. The series grew to more than 2,000 reports, of which nearly 1,300 are available in this digital collection.
Other CERs may be found in Mountain Scholar - Archives and Special Collections and in the Groundwater Data Collection.
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Browsing Civil Engineering Reports by Subject "Air -- Pollution"
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Item Open Access Applications of physical modeling to the investigations of air pollution problems in urban areas(Colorado State University. Libraries, 1974-03) Cermak, J. E. (Jack E.), author; Lombardi, David J., author; Thompson, R. S., author; Fluid Dynamics and Diffusion Laboratory, Department of Civil Engineering, Colorado State, publisherWind tunnel modeling of atmospheric flow and diffusion in the boundary layer over an urban area are discussed. Measurements were made over a model of an urban area composed of a network of uniform city blocks and streets. Two line sources emitting a radioactive tracer gas represented automobile emissions in a one-block length of a city street. Pollutant concentrations were calculated from samples of the tracer gas collected on building faces, in street canyons, and in the flow field above the model. Non dimensionalized concentration patterns were constructed from the analysis of the samples. Three wind directions were considered. The effects of a simple modification of the uniform model were evaluated.Item Open Access Feasibility of remote evaporation and precipitation estimates(Colorado State University. Libraries, 1974-04) Sadeh Z., Willz, author; Colorado State University, publisherItem Open Access Final report: numerical and physical models of urban heat islands(Colorado State University. Libraries, 1974-12) Meroney, Robert N., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherThe response in the atmosphere of stratified shear layers to nonhomogeneous surface features is the subject of this report. Many interesting atmospheric circulations such as the sea breeze, the urban heat island, and flow over a heated island in the ocean (heat mountain) are induced by unbalanced bouyancy forces as a result of differential surface temperature. Such phenomena are very complex since the motion is coupled with several dominant features such as thermal stratification, high roughness elements, nonuniformity of surface roughness and/or surface temperature, nonplanar boundaries, and unsteadiness of boundary conditions. These problems may be successfully examined, however, by a coordinated laboratory-analytical research effort. This report summarizes a numerical and experimental research program which examined such a complicated airflow over nonhomogeneous surface complexities in two- and three-dimensional space.Item Open Access Fluid modeling of exhaust gas dispersion for the University of Colorado School of Pharmacy: final report (July 1990-November 1990)(Colorado State University. Libraries, 1991) Parce, Douglas K., author; Meroney, Robert N., author; Fluid Mechanics and Wind Engineering Program, Department of Civil Engineering, Colorado State University?, publisherA wind-tunnel study was conducted in the Fluid Dynamics and Diffusion Laboratory at Colorado State University on a model of a planned addition to the University of Colorado Health Sciences Center (UCHSC). A 1:150 scale model of the new building, the School of Pharmacy (SOP) was added to an existing model of the UCHSC. It was used to collect information about the behavior of exhaust plumes and the probability of exhaust reentrainment into the new addition. Results are given in terms of normalized concentrations (K coefficients) to permit concentration estimates for alternative traffic, exhaust and wind speed combinations; but the decision as to the preferred configuration must be made with regard to current air-quality standards and building esthetics.Item Open Access Mass dispersion from an instantaneous line source in a turbulent shear flow(Colorado State University. Libraries, 1971-06) Putta, S. N., author; Cermak, J. E. (Jack E.), author; Fluid Dynamics and Diffusion Laboratory, College of Engineering Colorado State University, publisherDispersion of passive material released from an instantaneous line source in the constant stress region of a neutral atmosphere is investigated. Concentration fields within the cloud of dispersing material is represented by a three dimensional density function. This density function is divided into a marginal density function and a conditional longitudinal density function. The marginal density function gives the vertical spread of the material. This function has been derived from the semiempirical equation of dispersion, by using logarithmic velocity distribution for mean velocity and a linear variation for eddy diffusivity in the vertical direction. Longitudinal density function, which gives the longitudinal distribution of material within a given horizontal layer of the cloud, is constructed from the statistical properties of dispersion. Utilizing the Lagrangian similarity hypothesis for the concentration field, the semiempirical equation has been transformed into a similarity coordinate plane. Moment equations are derived from this equation using suitable boundary conditions. From these equations statistical properties are derived for mean, variance and skewness coefficients of the longitudinal density function. It is shown that the longitudinal density function can be well represented by the Gram-Charlier density simply by substituting the derived statistical properties. Ground level concentrations obtained by integration of this proposed density function agree qualitatively with observations in wind tunnels and field experiments.Item Open Access Stratified shear flows over a simulated three-dimensional urban heat island(Colorado State University. Libraries, 1973-08) SethuRaman, S., author; Cermak, J. E. (Jack E.), author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherThree-dimensional airflow over a rectangular heat island was studied for various conditions of approach flow in a wind tunnel. Three different thermal stratifications of the approach flow were selected for the study -- neutral, ground based and elevated inversions. For each of these flows studies were conducted with and without roughness over the heat island for the conditions with and without heating of the island. Approach flow temperature profiles were modeled according to atmospheric data available in the literature. For each of the twelve cases mentioned above, measurements of mean wind velocity, longitudinal velocity fluctuations, mean temperature and temperature fluctuations were made. In addition, mean concentration measurements of a radioactive gas released from a two-dimensional, ground-level line source upwind of the heat island were also made. Flow patterns were visualized for different cases with the help of a passive smoke source. Comparisons of data from the wind-tunnel measurements with the field data were made. Three-dimensional measurements of the mean wind velocity, temperature and turbulence have yielded valuable information concerning the flow of air around a typical urban heat island. The mechanisms of the heat island observed in the wind tunnel for different stratified flows were very similar to those observed in the field. The urban heat island plume that passes aloft downwind causes an appreciable reverse flow onto the heat island. The helical vortices at the edge of the heat island cause a reduction in the turbulence level resulting in high concentrations of the mass released from a continuous line source upwind of the heat island. A theoretical model based on linearized equations of motions incorporating a boundary layer type velocity profile has been developed to predict the urban excess temperatures and velocities. Theoretical results compare fairly well with data obtained in the laboratory and in the field.Item Open Access Wind-tunnel modeling of flow and diffusion over an urban complex(Colorado State University. Libraries, 1971) Chaudhry, Fazal Hussain, author; Cermak, Jack E., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisher