Download or read book MAC3D written by Robert S. Bernard and published by . This book was released on 1998 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MAC3D Numerical Model for Reservoir Hydrodynamics with Application to Bubble Diffusers written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MAC3D numerical model, a three dimensional flow solver initially developed for reservoir hydrodynamics, has been extended to account for the flow and gas transfer induced by bubble plumes. The latter are represented as buoyant columns in which dissolved gas is transferred to or from surrounding water. The local transfer rate is proportional to the dissolved gas concentration, and the resulting flow and gas transport are computed by solving discrete equations for the conservation of mass and momentum. The upward force imposed by a bubble column is directly proportional to the airflow rate through the associated bubble diffuser, and inversely proportional to the local depth and the bubble rise velocity. Gas transfer coefficients are empirical quantities that have to be inferred from laboratory experiments, but eddy viscosity and diffusivity are obtained directly from a k-E turbulence model. In the numerical solution of the governing equations, the explicit MacCormack scheme has been replaced by an implicit upwind scheme that improves stability and reduces execution time by a factor of five to ten. In this report, the model is validated for unstratified or weakly stratified water bodies by comparing predicted velocities and gas transfer rates with data from laboratory experiments and field tests using coarse and fine bubble diffusers.
Download or read book Water resources Investigations Report written by and published by . This book was released on 2000 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MAC3D written by Robert S. Bernard and published by . This book was released on 1998 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book One dimensional Simulation of Stratification and Dissolved Oxygen in McCook Reservoir Illinois written by Dale M. Robertson and published by . This book was released on 2000 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Review of Numerical Reservoir Hydrodynamic Modeling written by Billy H. Johnson and published by . This book was released on 1981 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stratification, i.e., density variations in a reservoir, occurs due to temperature variations as a result of surface heat exchange and plays an important role in determining the water quality of a reservoir. This role is determined through the influence of density variations on the movement of water in the reservoir. Therefore, the primary objective of a prediction of stratified flow hydrodynamics in reservoirs is to enable scientists to compute temperature distributions and water transports insofar as they affect various water quality parameters. One objective of the Environmental & Water Quality Operational Study (EWQOS) program of the U.S. Army Corps of Engineers is to provide District and Division offices with a tool for predicting reservoir hydrodynamics over periods of time extending from the initial setup of thermal stratification in the spring through its breakup in the fall. Such a predictive technique will subsequently be used in the prediction of water quality parameters. Both two- and three-dimensional, unsteady, variable density, heat-conducting models have been investigated during the past year. This investigation has centered around an analysis of both the mathematical and numerical bases of individual models as well as their ability to simulate a density underflow.
Download or read book A Hydrodynamic Numerical Model for Stratified Flow with Application to a Model Great Lake written by Anthony George Kizlauskas and published by . This book was released on 1972 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Resources and the Urban Environment 98 written by Thomas E. Wilson and published by . This book was released on 1998 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection contains 125 papers presented at the 1998 National Conference on Environmental Engineering, held in Chicago, Illinois, June 7-10, 1998.
Download or read book Physical Modeling of Reservoir Hydrodynamics written by Mark S. Dortch and published by . This book was released on 1985 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Development of a Three dimensional Numerical Model for Reservoir Hydrodynamics written by Robert S. Bernard and published by . This book was released on 1995 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Quality 96 written by and published by . This book was released on 1996 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental and Coastal Hydraulics written by International Association for Hydraulic Research. Congress and published by . This book was released on 1997 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Investigation of Metabolic Reductive Dechlorination in DNAPL Source Zones written by John Anthony Christ and published by . This book was released on 2005 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the most intractable environmental remediation problems are those involving the release of dense non-aqueous phase liquids (DNAPLs), such as chlorinated solvents, to the subsurface. Research efforts have focused on the use of numerical models to investigate reductions in contaminant concentrations due to partial mass removal and improvements in the performance of complementary source zone remediation technologies. Previous numerical investigations, however, have been limited to two-dimensional systems. Furthermore, a lack of models capable of simulating the most promising complementary technology, metabolic reductive dechlorination, has limited its application. This work developed and applied compositional multiphase numerical simulators to examine the influence of dimensionality (two-dimensions versus three-dimensions) on DNAPL source zone simulations and to investigate the benefits of stimulating metabolic reductive dechlorination at a chlorinated ethene-DNAPL contaminated site. Results from the dimensionality investigation showed that the simulation of DNAPL migration, entrapment, and dissolution in two dimensions provided reasonable approximations to the behavior simulated in three dimensions. Commonly employed saturation distribution and mass recovery metrics were approximately equivalent. Flux- averaged concentrations simulated in two dimensions, however, tended to be three to four times higher than those simulated in three dimensions. This difference was attributed to dilution at the down gradient boundary. An alternative metric, mass flux reduction, however, yielded better agreement.
Download or read book Use of Permeable Formwork in Placing and Curing Concrete written by P. G. Malone and published by . This book was released on 1999 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Permeable framework is a special class of lined formwork used to produce improvements in the strength and durability of concrete. The bracing and the liner in the formwork are engineered to resist the pressure of plastic (or fresh) concrete, but to allow trapped air and excess water to pass through and be removed during concrete placement and consolidation. The objective in using permeable formwork is to eliminate voids on the surface of the concrete (bug holes) and to increase the strength and durability of the concrete surface immediately behind the formwork. A review of permeable formwork and its use in placing concrete was conducted. Methods, techniques, and materials are discussed, and example applications are described. Benefits of using permeable formwork include a reduction in bug holes and surface defects, improved resistance to freezing and thawing, reduced rates of surface carbonation and chloride-ion infiltration, increased surface strength, reduced form coating requirements, reduced efforts in curing, and reduced surface preparation for coating. The cost of using permeable formwork varies greatly among job sites. However, the cost of using permeable formwork will generally be double that for conventional impermeable formwork. Cost savings can be realized in the extended life of any wooden formwork used behind the filter fabric, the ability to proceed without applying form-release compounds, the decreased cost of final surface preparation (if coatings are to be applied to the finished concrete), and the increased service life of the finished concrete.
Download or read book Standard Practice for Shotcrete written by American Society of Civil Engineers and published by American Society of Civil Engineers. This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asbestos Abatement Guideline Detail Sheets written by and published by . This book was released on 1992 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reliability Assessment of Breakwaters written by Jeffrey A. Melby and published by Washington, DC : U.S. Army corps of Engineers, Waterways Experiment Station. This book was released on 1997 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
