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Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report

Description: The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNS databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is outlined as follows. Section 2 shows an assessment of numerical algorithms that are best suited for the numerical simulation of compressible flows involving turbulence and shock phenomena. ...
Date: October 1, 2012
Creator: Lele, Sanjiva
Partner: UNT Libraries Government Documents Department

Buoyancy Induced Boundary Layer Flows in Geothermal Reservoirs

Description: Most of the theoretical study on heat and mass transfer in geothermal reservoirs has been based on numerical method. Recently at the 1975 NSF Workshop on Geothermal Reservoir Engineering, Cheng presented a number of analytical solutions based on boundary layer approximations which are valid for porous media at high Rayleigh numbers. according to various estimates the Rayleigh number for the Wairakei geothermal field in New Zealand is in the range of 1000-5000, which is typical for a viable geothermal field consisting of a highly permeable formation and a heat source at sufficiently high temperature. The basic assumption of boundary layer theory is that heat convective heat transfer takes place in a thin porous layer adjacent to heated or cooled surfaces. Indeed, numerical solutions suggest that temperature and velocity boundary layers do exist in porous media at high Rayleigh numbers. It is worth mentioning that the large velocity gradient existing near the heated or cooled surfaces is not due to viscosity but is induced by the buoyancy effects. The present paper is a summary of the work that we have done on the analytical solutions of heat and mass transfer in a porous medium based on the boundary layer approximations since the 1975 Workshop. As in the classical convective heat transfer theory, boundary layer approximations in porous layer flows can result in analytical solutions. Mathematically, the approximations are the first-order terms of an asymptotic expansion which is valid for high Rayleigh numbers. Comparison with experimental data and numerical solutions show that the approximations are also accurate at moderate values of Rayleigh numbers. For problems with low Rayleigh numbers where boundary layer is thick, higher-order approximations must be used. 9 refs., 5 figs.
Date: December 1, 1976
Creator: Cheng, Ping
Partner: UNT Libraries Government Documents Department

Geothermal Reservoir Engineering Research

Description: This report first describes reservoir engineering within the broad field of petroleum engineering. The report next describes the general pattern of reservoir engineering in terms of performance observations, hypothesis construction and testing, and reservoir development planning, and emphasizes the importance of searching for the hypothesis about the nature of the reservoir system derived from all known facts instead of a model that includes only selected fact. The history since 1900 of gas, oil, and geothermal reservoir engineering research is briefly described.
Date: December 1, 1976
Creator: Ramey, H.J. Jr. & Miller, Frank G.
Partner: UNT Libraries Government Documents Department

Experimental Investigation and High Resolution Simulator of In-Situ Combustion Processes

Description: Accurate simulation of in-situ combustion processes is computationally very challenging because the spatial and temporal scales over which the combustion process takes place are very small. In this current and eleventh report, we report on the development of a virtual kinetic cell (VKC) that aids the study of the interaction between kinetics and phase behavior. The VKC also provides an excellent tool for developing and testing specialized solvers for the stiff kinetics encountered in ISC processes.
Date: July 1, 2006
Creator: Gerritsen, Margot & Kovscek, Anthony R.
Partner: UNT Libraries Government Documents Department

Bench-scale experiments in the Stanford Geothermal Project

Description: The Stanford Geothermal Project bench-scale experiments are designed to improve the understanding of geothermal reservoir physics. Three sets of experiments are discussed in the following sections: (1) vapor pressure lowering in porous media due to capillarity and adsorption, (2) the effect of temperature on absolute permeability, and (3) the determination of steam-water relative permeability for drainage processes.
Date: January 1, 1978
Creator: Counsil, J.R.; Hsieh, C.H.; Ehlig-Economides, C.; Danesh, A. & Ramey, H.J., Jr.
Partner: UNT Libraries Government Documents Department

Experimental and Theoretical Studies of Liquid Injection into Vapour-Dominated Reservoirs

Description: We analyze the injection of liquid into a depleted geothermal reservoir using numerical, analytical and experimental techniques. We first investigate the injection of liquid at the base of a uniformly heated reservoir and show how an ascending liquid layer develops. Ahead of the liquid-vapor interface the temperature rises sharply and, for cases in which the permeability is sufficiently high, the vapor is approximately isobaric. The region immediately behind the advancing liquid-vapor interface is approximately isothermal and therefore, the fraction vaporizing is dependent on the reservoir superheat. When the reservoir is overlain by a supercooled zone, some of the vapor produced at the ascending liquid-vapor interface condenses. As a result, the amount of newly formed vapor available for subsequent extraction can be significantly reduced.
Date: January 1, 1995
Creator: Fitzgerald, S.D. & Woods, W.
Partner: UNT Libraries Government Documents Department

Radon in Geothermal Reservoir Engineering

Description: Two general types of information related to transit time are amenable to radon measurement experiments. Under steady flow conditions, changes in the radon source will result in changes in the radon concentration in produced geofluids. And under steady emanation conditions, changes in the flow regime will also result in changes in the radon concentration. Current interest has focused on the relationship between radon concentration and the flow regime in producing geothermal reservoirs. The paper describes actual and planned experiments using radon as a tracer at The Geysers and other reservoirs. 1 tab., 4 refs., 2 figs.
Date: December 1, 1976
Creator: Kruger, Paul & Gary, Warren
Partner: UNT Libraries Government Documents Department

Recent developments in well test analysis in the Stanford Geothermal Program

Description: In the past year a number of studies pertaining to geothermal well test analysis were conducted. In this paper a brief overview of progress on the following six subjects is presented: (1) earth tide effects on a closed reservoir, (2) transient pressure analysis of multilayered heterogeneous reservoirs, (3) interference testing with wellbore storage and skin at the producing well, (4) steam/water relative permeabilities, (5) transient rate and pressure buildup resulting from constant pressure production, and (6) transient pressure analysis of a parallelepiped reservoir.
Date: January 1, 1978
Creator: Ehlig-Economides, C.
Partner: UNT Libraries Government Documents Department

Physical Model Studies of Explosion-Fractured Geothermal Reservoirs

Description: Large scale utilization of geothermal energy will require means for enhanced energy extraction from geothermal reservoirs since the higher quality hydrothermal resources adequate for commercial electricity generation represent only a small fraction of the estimated resource base. Technologies are being developed for artificial fracturing of hydrothermal and dry hot rock geothermal resources to obtain adequate permeability for water circulation and to expose new rock surface area. Non-isothermal processes such as in-place boiling or artificial circulation of cooler fluids can be used to extract the energy from the fractured formation. To evaluate non-isothermal heat transfer processes, physical model studies were conducted in the Stanford Geothermal Program fractured-rock reservoir model capable of operating at a maximum pressure of 800 psig at 500ºF. The 17-ft{sup 3} physical model has been described previously [Hunsbedt, Kruger, and London (1975), Hunsbedt (1975), and Hunsbedt, Kruger and London (1976)]. A summary of the characteristics of the relatively large fracture-permeability rock systems tested in the model are summarized in Table 1. The porosity and permeability characteristics of these systems resembled those of fracture-stimulated ones created by high-energy explosives. 1 tab., 4 refs., 2 figs.
Date: December 1, 1976
Creator: Hunsbedt, Anstein; Iregui, Roberto; Kruger, Paul & London, A. Louis
Partner: UNT Libraries Government Documents Department

Pressure drawdown analysis for the Travale 22 well

Description: This work presents preliminary results on the analysis of drawdown data for Travale 22. Both wellhead pressure and flow rate data were recorded in this well for over a period of almost two years. In the past, Barelli et al. (1975) and Atkinson et al. (1977) presented the analysis of five pressure buildup tests. Figure 1 shows the Horner plot for these cases. They found that to have a good match in all cases, it was necessary to assume that the Travale 22 well is intersected by a partially penetrating vertical fracture in a parallel-piped whose bottom side is maintained at constant pressure (boiling front), as shown in Fig. 2. Atkinson et al. also presented an analysis for a pressure interface test run in the Travale-Radicondoli area. In this case, the Travale 22 well was flowing and the pressure recorded at wells R1, R3, R5, R6, R9, and Chl (see Fig. 3 ) . Analysis of these data showed that pressure interference in this reservoir can be matched by considering pure linear flow (Figs. 4 and 5 ) . This indicated the possible presence of a vertical fracture intersecting the Travale 22 well. It was determined that fracture is oriented along the N73{sup o}W direction. In addition, the pressure interference data showed that no boundary exists within 2 kilometers from the fracture plane. It was mentioned that linear flow should take place in both horizontal and vertical directions.
Date: January 1, 1978
Creator: Barelli, A.; Brigham, W.E.; Cinco, H.; Economides, M.; Miller, F.G.; Ramey, H.J., Jr. et al.
Partner: UNT Libraries Government Documents Department

Elucidating Bioreductive Transformations within Physically Complex Media: Impact on the Fate and Transport of Uranium and Chromium

Description: The greatest challenge to elucidating geochemical and biological chromium reduction in natural sediments is to create a sterile environment without destroying the chemical and physical properties of the system. In this study we determined the potential for geochemical and biological chromium reduction in a naturally reducing soil using carbon amendments and sterilization. To minimize alterations to the sediment samples, soils were sterilized via exposure to ?-irradiation which causes fewer changes in the physical and chemical properties of the soil compared to other methods of sterilization. The objective of our research was to determine if the absence of viable microorganisms significantly affected the extent of chromium reduction in a reducing soil. Our hypothesis was that if geochemical reduction pathways dominated the system then soil sterilization should have little to no effect on the amount and rate of chromium that was reduced. However, if the reduction of chromium in these soils was a synergistic process then significantly different amounts of chromium should be reduced in the sterilized versus non-sterilized samples.
Date: June 1, 2006
Creator: Jardine, P.M.; Bank, T.L.; Baldwin, M. E.; Fendorf, S.E.; Ginder-Vogel, M.A. & Kukkadapu, M.E.
Partner: UNT Libraries Government Documents Department

Field-Scale Evaluation of Biological Uranium Reduction and Reoxidation in the Near-Source Zone at the NABIR Field Research Center in Oak Ridge, TN

Description: We have now added ethanol intermittently for over 700 days. Ethanol has been added weekly with each injection lasting for a few days. We are now observing: (1) Uranium immobilization at 700-2000 mg/kg. Baseline levels before remediation were 30-500 mg/kg. (2) Uranium concentrations in groundwater at the monitoring wells have fallen below the U.S. drinking water standard (30 ppb). This is an important milestone. (3) XANES analyses for day 535 indicate 51% U(IV) at the inner loop injection well, 35% U(IV) at MLS well 101-2, and 28% U(IV) at the extraction well. These numbers indicate that U(IV) reduction is not localized to the injection well, and is spreading through the aquifer. (4) We have had success removing trace levels of oxygen from recirculated water by addition of sulfite and related compounds. These compounds also provide the added benefit that in removing oxygen that themselves are oxidized to sulfate, an important electron acceptor needed for maintenance of our system.
Date: June 1, 2006
Creator: Criddle, Craig S.
Partner: UNT Libraries Government Documents Department

22nd Texas Symposium on Relativistic Astrophysics

Description: The XXII Texas Symposium on Relativistic Astrophysics, jointly organized by the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), the Stanford Linear Accelerator Center, and the Physics Department of Stanford University, was held on December 13-17, 2004. Following the tradition of past Texas Symposia the presentations emphasized recent developments in Cosmology, High Energy Astrophysics and the frontiers between these and Gravitation and Particle Physics. This Symposium was attended by more than 500 colleagues from a spectrum of disciplines mentioned above. There were 9 Plenary Sessions, 3 Parallel Sessions and 2 Poster Sessions held during the five-day program, with 76 oral and 240 poster presentations. These are now documented on CD and in the eConf proceedings archive. Funding of $15,000 received from the DOE under award DE-FG02-05ER41362 was used for expenses related to facility, local transportation and administrative expenses.
Date: April 1, 2005
Creator: Bloom, Elliott
Partner: UNT Libraries Government Documents Department

Field-scale evaluation of biological uranium reduction and reoxidation in the near-source zone at the NABIR Field Research Center in Oak Ridge, TN

Description: The primary objective of the project is to advance the understanding and predictive capability of coupled hydrological, geochemical, and microbiological processes that control the in situ transport and bioremediation radionuclides and co-contaminants at multiple scales. Specific objectives include: (1) Investigate the feasibility of in situ bioremediation of uranium in a highly contaminated region within the subsurface of Area 3 of the DoE ERSP FRC (2) Using a variety of tracer strategies, develop and model a system that establishes hydraulic control of the target region for biostimulation (3) Perform long term in situ biostimulation studies that create a microbial communities capable of reducing residual nitrate to N2 and mobile U(VI) to sparingly soluble U(IV) (4) Use a variety of solid and solution phase interrogation techniques to quantify the extent of in situ reduction and immobilization of U(VI). (5) Investigate a variety of geochemical factors that influence the stability and possible reoxidation of reduced uranium.
Date: June 1, 2006
Creator: Criddle, Craig S.; Kitanidis, Peter; Fendorf, Scott; Wu, Weimin; Jardine, Philip M.; Zhou, Jizhong et al.
Partner: UNT Libraries Government Documents Department

Seismic and Rockphysics Diagnostics of Multiscale Reservoir Textures

Description: As part of our study on ''Relationships between seismic properties and rock microstructure'', we have continued our work on analyzing shale textures from scanning acoustic microscope images. Our analysis is now extended to over 280 images of shales, giving us better statistics. The shales cover a range of depths and maturity. We estimate different statistical measures for characterizing heterogeneity and textures from scanning acoustic microscope (SAM) images of shale microstructures. Characterizing and understanding the microgeometry, their textures, scales, and textural anisotropy is important for better understanding the role of microgeometry on effective elastic properties. We analyzed SAM images from Bakken shale, Bazhenov shale, and Woodford shale. We observed quantifiable and consistent patterns linking texture, shale maturity, and elastic P-wave impedance. The textural heterogeneity and P-wave impedance increase with increasing maturity (decreasing kerogen content), while there is a general decrease in textural anisotropy with maturity. We also found a reasonably good match between elastic impedance estimated from SAM images and impedance computed from ultrasonic measurements.
Date: May 1, 2004
Creator: Mavko, Gary
Partner: UNT Libraries Government Documents Department

Seismic and Rockphysics Diagnostics of Multiscale Reservoir Textures

Description: As part of our study on ''Relationships between seismic properties and rock microstructure'', we have studied (1) Kerogen-rich shales using Scanning Acoustic Microscopy and ultrasonic wave propagation. We find that an increase in elastic modulus with increasing kerogen maturity can be directly related to the microstructural acoustic impedance changes. A positive relation is established between microstructural changes and velocity variations as functions of kerogen maturity. (2) Elastic properties of clay minerals using Atomic Force Acoustic Microscopy and Scanning Acoustic Microscopy. We show the effect of clay minerals in contact zones as load-bearing constituents of rocks (3) Elastic properties of unconsolidated sediments in an effort to quantify attributes for detection of overpressures from seismic and for effects of stress-induced velocity anisotropy in sediments (4) We have initiated efforts for velocity upscaling to quantify long-wavelength and short-wavelength velocity behavior and the scale-dependent dispersion caused by sediment variability in different depositional environments.
Date: November 1, 2002
Creator: Mavko, Gary
Partner: UNT Libraries Government Documents Department

Seismic and Rockphysics Diagnostics fo Multiscale Reservoir Textures

Description: We have continued to finish up our work on analyzing relationships between elastic properties and rock microstructure. We have worked on theoretical models for the effects of sorting and packing on elastic moduli and seismic velocities. After analyzing the scanning acoustic images of shales to quantify textures at different scales, we are now using theoretical inclusion models to quantify the elastic property variation with texture. In the closing phases of this project most of our efforts are now focused on writing up the results and preparing the final reports.
Date: February 1, 2005
Creator: Mavko, Gary
Partner: UNT Libraries Government Documents Department

Compressional and shear wave velocities in water filled rocks during water-steam transition

Description: Both compressional and shear wave velocities were measured in water-filled Berea sandstone as a function of pore pressure under a constant confining pressure of 200 bar. At 145.5 C, compressional velocity increased from steam-saturated (low pore pressure) to water-saturated (high pore pressure) rock, whereas shear wave velocity decreased. Furthermore, a velocity minimum, attenuation and dispersions occur at water-steam transition for compressional wave. Results at 198 C show that both compressional and shear velocities decrease from steam-saturated to water-saturated rock, and a small velocity minimum is observed for compressional waves, but no attenuation nor dispersion occur. At both temperatures, the V{sub p}/V{sub s} ratio and Poisson's ratio increased from steam-saturated to water-saturated rock. The results are reasonably compatible with the mechanical effects of mixing steam and water fin the pore space near the phase transition, and may be applicable to in situ geothermal field evaluation.
Date: January 1, 1978
Creator: Hisao, Ito; DeVilbiss, John & Nur, Amos
Partner: UNT Libraries Government Documents Department

Isotopic Discrimination of Some Solutes in Liquid Ammonia.

Description: The nitrogen isotopic discrimination of some salts and metals, studied in liquid ammonia solution at -50ºC, decreases in magnitude in the order Pb{sup++}, Ca{sup++}, Li{sup+}, Ag{sup+}, Na{sup+}, Li, K{sup+}, Na, K. The isotopic discrimination appears to provide qualitative information about the strength of the cation-solvent interaction in liquid amonia.
Date: January 1, 1966
Creator: Viste, A. & Taube, H.
Partner: UNT Libraries Government Documents Department