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Flow Stability of Gas-Solids Suspensions: Final Report

Description: From abstract: One of the principal purposes of the work reported was to study the stability of gas-solids suspensions in the presence of a thermal gradient. Previously reported experience with unstable suspensions is summarized.
Date: February 1964
Creator: Wachtell, G. P. & Waggener, J. P.
Partner: UNT Libraries Government Documents Department

Numerical Methods for a Porous Medium Equation

Description: The degenerate parabolic equation has been used to model the flow of gas through a porous medium. Error estimates for continuous and discrete time finite element procedures to approximate the solution of this equation are proved and a new regularity result is described.
Date: August 1978
Creator: Rose, Michael Edward
Partner: UNT Libraries Government Documents Department

Flow of Gases Through Beds of Broken Solids

Description: Report issued by the Bureau of Mines over studies conducted on the effects of vapor flow through beds of broken solids. Methods and results of the studies are presented and discussed. This report includes tables, illustrations, and photographs.
Date: 1929
Creator: Furnas, C. C.
Partner: UNT Libraries Government Documents Department

A Note on the Transient Gas Flow Problem

Description: From abstract: "Expressions have been obtained for pressure distribution, velocity, volume flux, and total cumulative production of a gas well as a function of time after opening of a closed-down well... The calculations can be applied to problems involving short-term transient flow of gases, such as in experiments with radioactive tracers."
Date: June 1953
Creator: Sakakura, A. Y.
Partner: UNT Libraries Government Documents Department

Estimating large-scale fracture permeability of unsaturatedrockusing barometric pressure data

Description: We present a three-dimensional modeling study of gas flow inthe unsaturated fractured rock of Yucca Mountain. Our objective is toestimate large-scale fracture permeability, using the changes insubsurface pneumatic pressure in response to barometric pressure changesat the land surface. We incorporate the field-measured pneumatic datainto a multiphase flow model for describing the coupled processes ofliquid and gas flow under ambient geothermal conditions. Comparison offield-measured pneumatic data with model-predicted gas pressures is foundto be a powerful technique for estimating the fracture permeability ofthe unsaturated fractured rock, which is otherwise extremely difficult todetermine on the large scales of interest. In addition, this studydemonstrates that the multi-dimensional-flow effect on estimatedpermeability values is significant and should be included whendetermining fracture permeability in heterogeneous fracturedmedia.
Date: May 17, 2005
Creator: Wu, Yu-Shu; Zhang, Keni & Liu, Hui-Hai
Partner: UNT Libraries Government Documents Department

EOS3nn: An iTOUGH2 module for non-Newtonian liquid and gasflow

Description: This report documents the iTOUGH2 module EOS3nn, developed for modeling two-phase isothermal flow of a non-Newtonian liquid and a non-condensible gas in multidimensional, porous and fractured geologic media. This document supplements the TOUGH2 and iTOUGH2 user s guides and is therefore not a self-contained manual. It presents information on the physical processes modeled and the mathematical and numerical methods used. Also included are two sample problems for code testing and benchmarking. Modeling scenarios and approaches are discussed to illustrate problem setup and usage of the EOS3nn module.
Date: August 1, 2002
Creator: Wu, Yu-Shu; Finsterle, Stefan & Pruess, Karsten
Partner: UNT Libraries Government Documents Department


Description: A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.
Date: September 27, 2007
Creator: Lee, S & Richard Dimenna, R
Partner: UNT Libraries Government Documents Department

The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings. Interim Report

Description: A modified Reynolds equation is derived for gaslubricated hydrodynamic bearings operating under ''slip flow'' conditions. Closed analytical solutions are given for a Rayleigh-type step-bearing and an inclined plane slider bearing for the case of two-dimensional flow. The influence of the molecular mean free path on the performance of bearings of arbitrary form is obtained by means of a small parameter, perturbation technique. (auth)
Date: June 1, 1958
Creator: Burgdorfer, A.
Partner: UNT Libraries Government Documents Department


Description: An analysis is presented of the dynamics of a turboblower acting together with its connecting circuit. This is to be distinguished from the aero- thermodynamics involved in the design of the blower itself. The effect on system stability of blower and circuit characteristics is discussed. (auth)
Date: April 16, 1958
Creator: Furgerson, W.T.
Partner: UNT Libraries Government Documents Department

Membrane Oxygen Enrichment Cost and Application Evaluation

Description: A separation process, similar to the reverse osmosis membrane process for the desalination of water, can be used for the separation and enrichment of multi-component gas streams. The development of new processing methods and modular packing systems together with advanced commercialization of desalination systems now makes similar processes for gas separation appear feasible and economical. Composite membranes have been developed that are both thin enough to provide a large gas flow and strong enough to withstand the driving pressure of the incoming gas. This is done by depositing a polymer on the finely porous surface of a fabric-reinforced supporting membrane. The resulting material is then formed into a spiral-wound element that provides a large amount of membrane area in a small volume. Laboratory experiments using gas separation membranes by Fluid Systems Division of UOP and by General Electric Company have established the technical feasibility of using such membranes to produce oxygen-enriched air. A preliminary analysis of membrane oxygen enrichment economics was prepared by the Fluid System Division of UOP which shows that oxygen enrichment could be profitable for combustion systems up to 100 tons of oxygen per day. A supporting economic study made by Econergy Associates reaffirms the positive economic potential for a 1000-ton/day, 30% oxygen enrichment plant.
Date: March 1979
Creator: Fischer, J. & Burnett, Lowell J.
Partner: UNT Libraries Government Documents Department


Description: The conceptual design of the Coupled Breeding Superheating Reactor, CBSR, for achieving a positive breeding gain and for producing 65 Mw of electric power is presented. The design combines a steam-cooled fast region and a nonboiling pressurized light-water-cooled thermal region. The advantage offered by this arrangement as compared with that using a solid moderator in the thermal zone is that, if a power excursion occurs, the water will increase the void content and tend to limit the excursion. The total reactor power is 216 Mwt, of which 163 Mwt is used to superheat steam as it passes through the fast regions of the reactor and 53 Mwt is transferred to the pressurized water. For this power split the fast core is 4% subcritical without the reactivity contribution of the thermal region. A breeding ratio of 1.4 is calculated for an oxide-fueled fast and thermal core and a high-density, metal-fueled radial blanket. The steam throttle conditions produced are 75 atm and 453 deg C for an average fast-core power density of 500 Mw/l. The original goal of 565 deg C throttle steam temperature and 1 Mw/l power density was compromised because of the surface temperature limitation of currently available cladding materials. The system does not require a large external power source for producing the steam introduced into the fast core. This is possible through the use of a steam compressor that increases the pressure of a portion of the superheated steam and thus permits its use to generate the required saturated-steam flow rate by vaporizing the feedwater from the steam cycle. The design includes a pressure-balance system that equalizes the static pressure in both the pressurized-water and steam systems. The pressure-balance system provides a means of cooling the steam regions in an emergency by allowing the pressurized water to flash. These ...
Date: March 1, 1961
Creator: Avery, R.; Dewey, W.V.; Rohde, R. & Toppel, B.J.
Partner: UNT Libraries Government Documents Department

Numerical Methods for a Porous Medium Equation

Description: The degenerate parabolic equation has been used to model the flow of gas through a porous medium. Error estimates for continuous and discrete time finite element procedures to approximate the solution of this equation are proved and a new regularity result is described.
Date: August 1978
Creator: Rose, M. E.
Partner: UNT Libraries Government Documents Department

Forced convection and transport effects during hyperbaric laser chemical vapor deposition

Description: This work explores mass transport processes during HP-LCYD, including the transverse forced-flow of precursor gases through a nozzle to enhance fiber growth rates. The use of laser trapping and suspension of nano-scale particles in the precursor flow is also described, providing insights into the nature of the gas flow, including jetting from the fiber tip and thermodiffusion processes near the reaction zone. The effects of differing molecular-weight buffer gases is also explored in conjunction with the Soret effect, and it is found that nucleation at the deposit surface (and homogeneous nucleation in the gas phase) can be enhanced/ retarded, depending on the buffer gas molecular weight. To demonstrate that extensive microstructures can be grown simultaneously, three-dimensional fiber arrays are also grown in-parallel using diffractive optics--without delatory effects from neighboring reaction sites.
Date: January 1, 2009
Creator: Maxwell, James L; Chavez, Craig A; Espinoza, Miguel; Black, Marcie; Maskaly, Karlene & Boman, Mats
Partner: UNT Libraries Government Documents Department