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 flow"
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Item Open Access Flow around a cylinder with non-uniform approach velocity numerical techniques of integration: preliminary results(Colorado State University. Libraries, 1968-08) Di Silvio, G. (Gianpaolo), 1938-, author; Petryk, Sylvester, author; Colorado State University, publisherItem Open Access Research and development technique for estimating airflow and diffusion parameters in connection with the Atmospheric Water Resources Program: annual report(Colorado State University. Libraries, 1970) Orgill, Montie M., author; Cermak, Jack E., author; Grant, Lewis O., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherItem Open Access Research and development technique for estimating airflow and diffusion parameters in connection with the Atmospheric Water Resources Program: interim report(Colorado State University. Libraries, 1969-02) Cermak, J. E. (Jack E.), author; Grant, Lewis O., author; Orgill, Montie M., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherPreliminary experiments on transport and dispersion over a 1:9,600 scale model of the Eagle River Valley and topography surrounding Climax, Colorado were obtained in the Colorado State University meteorological wind tunnel. Geometric, dynamic and thermal similarity are considered, primarily, for neutral stability flows. Similarity for transport and dispersion is considered briefly. Pilot balloon flights, a super pressure balloon flight and ice nuclei concentrations taken during a field trip in the Climax area are presented.Item Open Access Research and development technique for estimating airflow and diffusion parameters in connection with the Atmospheric Water Resources Program: interim report(Colorado State University. Libraries, 1971) Orgill, Montie M., author; Cermak, J. E. (Jack E.), author; Grant, Lewis O., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherThis report presents a summary of the research and tentative findings on the use of scaled topographic models and laboratory techniques to study the transport and dispersion of cloud seeding material over mountainous terrain. Three mountainous areas along the continental divide have been selected by the Bureau of Reclamation for such studies. Each area has cloud seeding programs in progress.Item Open Access Research and development technique for estimating airflow and diffusion parameters in connection with the Atmospheric Water Resources Program: interim report(Colorado State University. Libraries, 1970) Orgill, Montie M., author; Cermak, Jack E., author; Grant, Lewis O., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherItem Open Access Research and development technique for estimating airflow and diffusion parameters in connection with the Atmospheric Water Resources Program: final report(Colorado State University. Libraries, 1969-08) Cermak, J. E. (Jack E.), author; Grant, Lewis O., author; Orgill, Montie M., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherA stably stratified atmospheric boundary layer was simulated in a wind tunnel and utilized to determine radioactive krypton dispersion patterns over a 1:9600 scale model of the Eagle River Valley and topography surrounding Climax, Colorado. Geometric, dynamic, and thermal similarity are considered, primarily, for barostromatic airflow. Similarity criteria for transport and dispersion are considered also. This is the first time that a barostromatic airflow produced by cooling with dry ice has been documented by temperature and velocity profile measurements. Field Gata indicate that airflow and temperature characteristics over the model are approximately similar to a prototype storm. Dispersion measurements were taken by using sources representative of field ground sources. Model and field measurements confirm that seeding nuclei are reaching the target area from the present existing ground sources. Limited field measurements of ice nuclei concentrations at Chalk Mountain show a variation of 5 to 300 part./liter or XU/Q ~ 1 x 10 -9m-2 to 68 x 10-9m-2. Concentration values deduced from radioactive gas measurements over the model show values within the same range but closer to the optimum values indicated by present cloud physics models, i.e., XU/Q ~ 15 to 18 x 10-9m-2. The barostromatic airflow model indicated that topography plays an important role in determining the downwind direction of the particulate plume.Item Open Access Research and development technique for estimating airflow and diffusion parameters related to the Atmospheric Water Resources Program: final report(Colorado State University. Libraries, 1971) Orgill, Montie M., author; Cermak, Jack E., author; Grant, Lewis O., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherItem Open Access Response of a turbulent boundary layer to lateral roughness discontinuities(Colorado State University. Libraries, 1972-07) Wang, Hua, author; Nickerson, Everett C., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherThe structure of the turbulent boundary layer on a flat plate consisting of alternate, longitudinal strips of smooth and rough (Sand paper, Grit 4) surfaces parallel to the direction of the flow has been investigated. Measurements of mean velocity, wall shear stress, turbulent intensities, turbulent shear stresses and energy spectra of the streamwise turbulent velocity were obtained. The flow field can be subdivided into three regions. These are: (a) the "smooth" region along the centerline of each smooth strip; (b) the "rough" region along the centerline of each rough strip; and (c) the "intermediate" region lying between the smooth and the rough regions. In both smooth and rough regions, the flow conditions are found to be nearly analogous to those in two-dimensional boundary layers over smooth and rough walls, respectively. In the intermediate region the wall shear stress was found to adjust itself very rapidly to the local conditions of the wall while going from the smooth to the rough region. The vertical distribution of mean velocity can satisfactorily be expressed by the two-dimensional descriptions for the law of the wall and the velocity-defect law. However, the two laws are not universal but form a family of curves depending on the local wall shear stress. The spanwise change from smooth-wall conditions to rough-wall conditions will induce a weak cross-flow directed from the rough to the smooth region near the wall. A theoretical description of the turbulent shear stress -vw which is responsible for the generation of this cross-flow has been presented. The spanwise adjustment of turbulent quantities to local conditions of the wall takes place at a slower rate than does the wall shear stress. The normalized spectra of the streamwise turbulent velocity remains largely unaffected by the surface configuration investigated here.Item Open Access The stability of parallel, quasi-parallel and stationary flows(Colorado State University. Libraries, 1973-09) Kahawita, Rene A., author; Meroney, Robert N., author; Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, publisherThe methods of linear perturbation theory have been used to study the stability of various flows, among them being (i) The stability of boundary layers along concave heated walls; (ii) The stability of boundary layers along concave walls with suction; (iii) The stability of wall jets along concave and convex walls; (iv) The spin up of a two-dimensional cylinder in an infinite medium; (v) The stability of stationary layers of fluid with arbitrary temperature stratification; (vi) The stability of natural convection flow along inclined plates. During the course of this work, three different solution techniques were employed; one of them was an approximate analytic technique, the remaining two were numerical. Three-dimensional spatially and temporally amplifying disturbances were considered in this study. The results indicated that the normal velocity component of the mean flow in a boundary layer, although much smaller than the stream wise component had a profound effect in reducing the stability of the flow. On the other hand, suction at the wall improved the stability characteristics. For the flow of parallel layers of fluid along heated walls with small curvature, it was found that a unique stability curve for neutral disturbances may be obtained if the quantity plotted along the abscissa is Ra + KsNg2 where Ra is the Rayleigh number, Ng is the Goertler number and Ks is a constant which expresses the relative importance of the mean temperature and velocity profiles. It was demonstrated also that wall jets are unstable on concave as well as convex walls. The results obtained for the stability of the spin up of a cylinder in an infinite medium are in qualitative agreement with experiment. The dependence of the onset of convective overturning in an unstable layer of fluid with a nonlinear basic temperature profile and bounded above by fluid of varying stability on Rayleigh number was established. The angle at which the two-dimensional wave instability passes into the three-dimensional mode in natural convection along an inclined plate was calculated. The result was found to be in good agreement with experiment. Other results obtained for this flow were in good qualitative agreement with experiment. Finally, some simple wind tunnel experiments with boundary layers along curved heated walls were performed. Photographic evidence of longitudinal vortices was obtained together with some qualitative data.