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Pressure losses in fracture-dominated reservoirs: the wellbore constriction effect

Description: Improved energy production from many types of energy reservoirs such as hot dry rock geothermal as well as hydraulically fractured oil, gas, and other geothermal reservoirs requires a better understanding of the fluid mechanics in the vicinity of the fracture-wellbore intersection. Typically, the aperture (smallest dimension) of a hydraulic fracture is only of the order of 1 mm (0.04 in.) so that reasonable energy production rates from geothermal systems require fairly large flow velocities wit… more
Date: January 1, 1980
Creator: Murphy, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Numerical analysis of laminar forced convection in a spherical annulus

Description: Calculations of steady laminar incompressible fluid-flow and heat transfer in a spherical annulus are presented. Steady pressures, temperatures, velocities, and heat transfer coefficients are calculated for an insulated outer sphere and a 0/sup 0/C isothermal inner sphere with 50/sup 0/C heated water flowing in the annulus. The inner sphere radius is 13.97 cm, the outer sphere radius is 16.83 cm and the radius ratio is 1.2. The transient axisymmetric equations of heat, mass, and momentum conser… more
Date: July 21, 1980
Creator: Tuft, D.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Condensation film coefficients for mixtures of isobutane and isopentane

Description: Research designed to obtain baseline data on heat transfer for working fluids in geothermal binary cycle systems is described. The working fluid loop in the experimental apparatus simulates the binary cycle with steam as the heating fluid and a throttling valve instead of the turbine. Data on film coefficient for the condensation of 90/10 and 80/20 mixtures of isobutane-isopentane on a horizontal tube at various temperatures and condensation rates are presented. Data indicate that mixtures of i… more
Date: May 1, 1980
Creator: Tleimat, B.W.; Rie, H.; Laird, A.D.K. & Zhao, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Experimental study of the steady natural convection in a horizontal annulus with irregular boundaries

Description: The natural convective heat transfer across an annulus with irregular boundaries was studied using a Mach-Zehnder interferometer. The annulus was formed by an inner hexagonal cylinder and an outer concentric circular cylinder. This configuration models, in two dimensions, a liquid metal fast breeder reactor spent fuel subassembly inside a shipping container. During the test, the annulus was filled with a single gas, either neon, air, argon, krypton, or xenon, at a pressure of about 0.5 MPa. Fro… more
Date: January 1, 1980
Creator: Boyd, R.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of shear on vortex shedding patterns in high Reynolds number flow: an experimental study

Description: Vortex shedding has been identified as a potential major source of loading on the Ocean Thermal Energy Conversion (OTEC) Plant Cold Water Pipe (CWP). To gain a better understanding of the vortex shedding phenomena, a series of model tests has been conducted. The results of this investigation are presented. The effects of current shear on vortex shedding patterns in high Reynolds number (R/sub e/) flow around a circular cylinder used to model the OTEC CWP are addressed. Tests were conducted in a… more
Date: unknown
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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[Bifurcations and Patterns in Nonlinear Dissifative Systems]

Description: This report discusses the following topics: Rayleigh-Benard convection with an imposed horizontal flow; Rayleigh-Benard convection in a gas under non-boussinesq conditions; electro- convection in a nematic liquid crystal; and Rayleigh-Benard convection in a nematic liquid crystal. (LSP)
Date: February 26, 1992
Creator: Ahlers, G. & Cannell, D. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis, scientific computing and fundamental studies in fluid mechanics

Description: Progress is reported on work in the following areas: vortex dynamics and turbulence, fingers and bubbles in Hele-Shaw cells and unbounded fluid, vortex reconnection, pattern selection in solidifying systems, Richtmyer-Meshkov instability, Wavy-Taylor vortex flows, high reynolds number laminar flows, and lastly numerical analysis and dynamical systems. (GHH)
Date: January 1, 1991
Creator: Keller, H.B. & Saffman, P.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of a building wake/stack height numerical modeling capability

Description: We are developing state-of-the-art numerical tools which can be used to provide reliable estimates of potential emissions at various LLNL sites. In particular we have focused our efforts in generating models which can simulate the wind flow and dispersion of airborne pollutants around surface-mounted structures such as buildings or building complexes. To achieve this goal, we have adopted two different but complementary approaches in the modeling of this complex problem. The first approach empl… more
Date: September 6, 1991
Creator: Lee, R.L. & McCallen, R.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Verification Test Suite (VERTS) For Rail Gun Applications using ALE3D: 2-D Hydrodynamics & Thermal Cases

Description: A verification test suite has been assessed with primary focus on low reynolds number flow of liquid metals. This is representative of the interface between the armature and rail in gun applications. The computational multiphysics framework, ALE3D, is used. The main objective of the current study is to provide guidance and gain confidence in the results obtained with ALE3D. A verification test suite based on 2-D cases is proposed and includes the lid-driven cavity and the Couette flow are inves… more
Date: April 17, 2008
Creator: Najjar, F M; Solberg, J & White, D
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Computational design and analysis of flatback airfoil wind tunnel experiment.

Description: A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the… more
Date: March 1, 2008
Creator: Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA) & Berg, Dale E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Resistive stability of the cylindrical spheromak

Description: The growth rates for resistive instabilities in a straight circular cylinder with spheromak profiles are computed by using two complementary methods. The first method employs boundary layer analysis and asymptotic matching, most valid for values of the magnetic Reynolds number S greater than or equal to 10/sup 5/. The second method solved the full linearized resistive MHD equations as an initial value problem, utilizing zone packing around the mode rational surface. Resolution requirements limi… more
Date: November 1, 1983
Creator: DeLucia, J.; Jardin, S. C. & Glasser, A. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fluid forces on two circular cylinders in crossflow

Description: Fluid excitation forces are measured in a water loop for two circular cylinders arranged in tandem and normal to flow. The Strouhal number and fluctuating drag and lift coefficients for both cylinders are presented for various spacings and incoming flow conditions. Results show the effects of Reynolds number, pitch ratio, and upstream turbulence on the fluid excitation forces.
Date: June 1, 1985
Creator: Jendrzejczyk, J.A. & Chen, S.S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Design of the Glenwood Springs downhole heat exchanger

Description: A heat exchanger has been designed to obtain 250,000 Btu/hr from a 20-in.-diameter geothermal well at various brine temperatures. The system consists of a 10-in.-diameter plastic pipe to promote convective flow in the well and a 4-in.-diameter, Schedule 40 steel U-tube containing distilled water to extract the energy. Subject to the validity of the major assumptions, the required lengths of one leg of the U-tube at various brine temperatures are 34 ft (150/sup 0/F), 42 ft (140/sup 0/F), 54 ft (… more
Date: April 1, 1982
Creator: Chiu, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Multiple time scale methods in tokamak magnetohydrodynamics

Description: Several methods are discussed for integrating the magnetohydrodynamic (MHD) equations in tokamak systems on other than the fastest time scale. The dynamical grid method for simulating ideal MHD instabilities utilizes a natural nonorthogonal time-dependent coordinate transformation based on the magnetic field lines. The coordinate transformation is chosen to be free of the fast time scale motion itself, and to yield a relatively simple scalar equation for the total pressure, P = p + B/sup 2//2..… more
Date: January 1, 1984
Creator: Jardin, S. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fluid forces on two circular cylinders in crossflow

Description: Fluid excitation forces are measured in a water loop for two circular cylinders arranged in tandem and normal to flow. The Strouhal number and fluctuating drag and lift coefficients for both cylinders are presented for various spacings and incoming flow conditions. The results show the effects of Reynolds number, pitch ratio, and upstream turbulence on the fluid excitation forces.
Date: January 1, 1986
Creator: Jendrzejczyk, J.A. & Chen, S.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A parallel numerical simulation for supersonic flows using zonal overlapped grids and local time steps for common and distributed memory multiprocessors

Description: Parallel Navier-Stokes codes are developed to solve both two- dimensional and three-dimensional flow fields in and around ramjet and nose tip configurations. A multi-zone overlapped grid technique is used to extend an explicit finite-difference method to more complicated geometries. Parallel implementations are developed for execution on both distributed and common-memory multiprocessor architectures. For the steady-state solutions, the use of the local time-step method has the inherent advanta… more
Date: January 1, 1989
Creator: Patel, N.R.; Sturek, W.B. & Hiromoto, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Weak- and strong-turbulence regimes of the Hasegawa-Mima equation

Description: A Kolmogorov-type analysis of the energy- and enstrophy-cascading ranges of the forced Hasegawa-Mima equation allows one to derive a criterion for the threshold of the transition between the weak turbulence and the strong turbulence regimes. It is found that, due to the inverse energy cascade, the large-scale portion of the inertial range is in the strong turbulence regime in the limit of infinite Reynolds-like numbers.
Date: February 1, 1992
Creator: Ottaviani, M. & Krommes, J.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Flatback airfoil wind tunnel experiment.

Description: A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the… more
Date: April 1, 2008
Creator: Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA) & Berg, Dale E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effects of WENO flux reconstruction order and spatial resolution on reshocked two-dimensional Richtmyer-Meshkov instability

Description: Finite-difference weighted essentially non-oscillatory (WENO) simulations of the reshocked two-dimensional single-mode Richtmyer-Meshkov instability using third-, fifth- and ninth-order spatial flux reconstruction and uniform spatial grid resolutions corresponding to 128, 256 and 512 points per initial perturbation wavelength are presented. The dependence of the density, vorticity, simulated density Schlieren and baroclinic production fields, mixing layer width, circulation deposition, mixing p… more
Date: March 16, 2006
Creator: Latini, M; Schilling, O & Don, W
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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PIV Experiments to Measure Flow Phenomena in a Scaled Model of a VHTR Lower Plenum

Description: A report of experimental data collected at the Matched-Index-of-Refraction (MIR) Laboratory in support of contract DE-AC07-05ID14517 and the INL Standard Problem on measurements of flow phenomena occurring in a lower plenum of a typical prismatic VHTR concept reactor to assess CFD code is presented. Background on the experimental setup and procedures is provided along with several samples of data obtained from the 3-D PIV system and an assessment of experimental uncertainty is provided. Data co… more
Date: September 1, 2006
Creator: Hugh M. McIlroy, Jr.; McEligot, Donald M.; Schultz, Richard R.; Christensen, Daniel; Pink, Robert J. & Johnson, Ryan C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Measurement of Flow Phenomena in a Lower Plenum Model of a Prismatic Gas-Cooled Reactor

Description: Mean-velocity-field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. The data were obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered for assessing computational fluid dynamics (CFD) software. This experiment has been sel… more
Date: May 1, 2008
Creator: Hugh M. McIlroy, Jr.; McEligot, Donald M. & Pink, Robert J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Investigation of Tractor Base Bleeding for Heavy Vehicle Aerodynamic Drag Reduction

Description: One of the main contributors to the aerodynamic drag of a heavy vehicle is tractor-trailer gap drag, which arises when the vehicle operates within a crosswind. Under this operating condition, freestream flow is entrained into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the aerodynamic drag. While a number of add-on devices, including side extenders, splitter plates, vortex stabilizers, and gap sealers, have been previously tested to alleviat… more
Date: October 25, 2007
Creator: Ortega, J; Salari, K & Storms, B
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Feasibility study for use of the natural convection shutdown heat removal test facility (NSTF) for VHTR water-cooled RCCS shutdown.

Description: In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance … more
Date: August 31, 2007
Creator: Tzanos, C. P. & Farmer, M. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

IDAHO NATIONAL LABORATORY PROGRAM TO OBTAIN BENCHMARK DATA ON THE FLOW PHENOMENA IN A SCALED MODEL OF A PRISMATIC GAS-COOLED REACTOR LOWER PLENUM FOR THE VALIDATION OF CFD CODES

Description: The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a typical prismatic gas-cooled (GCR) reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A detailed description of the model, scaling, the experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples … more
Date: September 1, 2008
Creator: Jr., Hugh M. McIlroy; McEligot, Donald M. & Pink, Robert J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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