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Development of a computer program for reactor core thermal hydraulics: finite differencing in a 3-D staggered mesh suitable for irregular boundary applications

Description: A formulation utilizing a finite difference scheme for the direct numerical simulation of time varying two-phase flow problems in three space dimensions with irregular boundary geometry is presented. The formulation of such problems introduces a complicated set of coupled non-linear partial differential equations for the conservation of mass, momentum, energy, appropriate constitutive equations, and equations of state coupling the two phases. Discretization of the partial differential equations… more
Date: unknown
Creator: Sha, W.T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Report of Modeling of CWM Droplet Combustion

Description: The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This proce… more
Date: October 1, 1983
Creator: Pandalai, Krish; Aggarwal, Suresh & Sirignano, William
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Potential effects of maternal contribution on egg and larva population dynamics of striped bass: Integrated individual-based model and directed field sampling

Description: We have used a bioenergetically-driven, individual-based model (IBM) of striped bass as a framework for synthesizing available information on population biology and quantifying, in a relative sense, factors that potentially affect year class success. The IBM has been configured to simulate environmental conditions experienced by several striped bass populations; i.e., in the Potomac River, MD; in Hudson River, NY; in the Santee-Cooper River System, SC, and; in the San Joaquin-Sacramento River S… more
Date: January 1, 1991
Creator: Cowan, J.H., Jr. (Maryland Univ., Solomons, MD (United States). Chesapeake Biological Lab.) & Rose, K.A. (Oak Ridge National Lab., TN (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Non-linear numerical studies of the tearing mode

Description: A non-linear, time dependent, hydromagnetic model is developed and applied to the tearing mode, one of a class of instabilities which can occur in a magnetically confined plasma when the constraint of infinite conductivity is relaxed. The model is based on the eight partial differential equations of resistive magnetohydrodynamics (MHD). The equations are expressed as a set of conservation laws which conserves magnetic flux, momentum, mass, and total energy. These equations are then written in g… more
Date: January 1, 1978
Creator: Schnack, D.D. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transient thermal analysis of three fast-charging latent heat storage configurations for a space-based power system

Description: A space-based thermal storage application must accept large quantities of heat in a short period of time at an elevated temperature. A model of a lithium hydride phase change energy storage system was used to estimate reasonable physical dimensions for this application which included the use of a liquid metal heat transfer fluid. A finite difference computer code was developed and used to evaluate three methods of enhancing heat transfer in the PCM energy storage system. None of these three met… more
Date: January 1, 1988
Creator: Stovall, T. K. & Arimilli, R. V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Full-wave calculations in flux coordinates for toroidal geometry

Description: A new 2-D full-wave code, HYPERION, employing a poloidal and toroidal mode expansion and including the toroidal terms arising in the wave equation has been developed. It is based on the existing modules developed for the MHD stability codes and uses as input the tokamak equilibria calculated with the RSTEQ code. At present the plasma response is described by the collisionally broadened cold plasma conductivity. However, the code is written in straight field line coordinates, this permits the ac… more
Date: January 1, 1988
Creator: Carreras, B. A.; Lynch, V. E.; Jaeger, E. F. & Batchelor, D. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An iterative algorithm to produce a positive definite correlation matrix from an approximate correlation matrix (with a program user's guide)

Description: This report contains an explanation of an algorithm that, when executed, will operate on any symmetric approximate correlation matrix by iteratively adjusting the eigenvalues of this matrix. The objective of this algorithm is to produce a valid, positive definite, correlation matrix. Also a description of a program (called POSDEF) which implements the algorithm is given.
Date: June 1, 1982
Creator: Iman, R.L. & Davenport, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of Celotex trademark charring depths in the DT-18 shipping container

Description: Celotex {trademark}, the insulating material used between the outer and inner containers of the DT-18 shipping package, undergoes decomposition, combustion, or both when heated to temperatures exceeding 150{degrees}C. Several DT-18 packages that had previously undergone hypothetical thermal accident testing were opened and Celotex {trademark} charring depths ranging from {1/2} to 1 {1/2} in. were recorded. The majority of char depth data taken was between 3/4 and 1 {1/4} in. One-dimensional HEA… more
Date: March 1, 1992
Creator: Anderson, J.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Manual for COMSYN: A orbit integration code for the study of beam dynamics in compact synchrotrons

Description: COMSYN is a numerical integration code which is written for the study and design of the compact synchrotrons. An improved 4th-order Runge-Kutta method is used in COMSYN to integrate the exact equations of motion in a rectangular coordinate system. The magnetic field components of the dipole B{sub x}, B{sub y} and B{sub z} can be obtained from either measurement or directly computed data (MAGNUS, TOSCA). A spline interpolation method is then used to get the field value at the particle position. … more
Date: October 1, 1991
Creator: Huang, Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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RODCON: a finite difference heat conduction computer code in cylindrical coordinates

Description: RODCON, a finite difference computer code, was developed to calculate the internal temperature distribution of the fuel rod simulator (FRS) for the Core Flow Test Loop (CFTL). RODCON solves the implicit, time-dependent forward-differencing heat transfer equation in 2-dimensional (Rtheta) cylindrical coordinates at an axial plane with user specified radial material zones and surface conditions at the FRS periphery. Symmetry of the boundary conditions of coolant bulk temperatures and film coeffic… more
Date: September 16, 1980
Creator: Conklin, J. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Prediction of the migration of several radionuclides in ocean sediment with the computer code IONMIG: a preliminary report

Description: A computer code, IONMIG, which is used to calculate the far-field transport of radionuclides through ocean sediment by diffusion and convection is described. The code uses a two-dimensional, axisymmetric, explicit finite difference formulation. Preliminary results for several species (Cs, Pu, I, Tc) are given.
Date: May 1, 1980
Creator: Russo, A.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A survey of air flow models for multizone structures

Description: Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 5… more
Date: March 1, 1991
Creator: Feustel, H.E. & Dieris, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Three-dimensional thermal analysis of a baseline spent fuel repository

Description: A three-dimensional thermal analysis has been performed using finite difference techniques to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplace… more
Date: June 5, 1980
Creator: Altenbach, T.J. & Lowry, W.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Field calculation algorithm for general beam distributions

Description: This note is a summary of the algorithm used in our recent paper on the coherent beam-beam interaction. The goal of the work was to study coherent beam-beam interactions, and the development needed was to avoid using the expression for the beam-beam generated fields that assumes a Gaussian beam distribution. Because of our interest in round beams the algorithm was developed for use with beams that are approximately round. We believe there is a similar approach for flat beams, but the Fourier se… more
Date: August 1, 1991
Creator: Krishnagopal, S. (Lawrence Berkeley Lab., CA (United States)) & Siemann, R. (Stanford Linear Accelerator Center, Menlo Park, CA (United States))
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A subregion block iteration to 3-D finite element modeling of subsurface flow

Description: A subregion block iteration (SBI) technique has been developed in conjunction with finite element approximations of saturated-unsaturated flow equations. The proposed SBI technique is implemented in a three-dimensional finite element saturated-unsaturated flow model. The model is verified with a nonlinear diffusion equation having an analytical solution. It is then applied to a burial trench problem. It is not possible to solve this field problem using the direct elimination finite element meth… more
Date: January 1, 1988
Creator: Yeh, G.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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HEATING 7. 1 user's manual

Description: HEATING is a FORTRAN program designed to solve steady-state and/or transient heat conduction problems in one-, two-, or three- dimensional Cartesian, cylindrical, or spherical coordinates. A model may include multiple materials, and the thermal conductivity, density, and specific heat of each material may be both time- and temperature-dependent. The thermal conductivity may be anisotropic. Materials may undergo change of phase. Thermal properties of materials may be input or may be extracted fr… more
Date: July 1, 1991
Creator: Childs, K.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Finite-difference methods in multi-dimensional two-phase flow. [BWR; PWR; LMFBR]

Description: In the summer of 1974, the Theoretical Division of the Los Alamos Scientific Laboratory began several research programs in the area of reactor safety for the United States Nuclear Regulatory Commission. Research efforts were started in the Liquid Metal Fast Breeder (LMFBR) and the Light Water Reactor (LWR) safety programs. The character of the Theoretical Division was to develop computer codes for the safety analysis of these reactor systems. The question of whether or not, during the course of… more
Date: January 1, 1977
Creator: Travis, J. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ion-temperature-gradient instability in toroidal plasmas

Description: The stability of the ion-temperature-gradient mode in a toroidal plasma is investigated. Using the ballooning-mode formalism, an ordinary difference-differential equation is derived which includes full kinetic effects. The equation is, then, examined in various limits where it reduces to an ordinary differential equation. Analytic and computational studies show that, for eta/sub i/ identical with d lnT/sub i//d lnn > 1, toroidal effects further destabilize the mode and, hence, the corresponding… more
Date: March 1, 1980
Creator: Guzdar, P.N.; Chen, L.; Tang, W.M. & Rutherford, P.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A computer program for the 2-D magnetostatic problem based on integral equations for the field of the conductors and boundary elements

Description: The iterative design of the 2-dimensional cross section of a beam transport magnet having infinitely permeable iron boundaries requires a fast means of computing the field of the conductors. Solutions in the form of series expansions are used for rectangular iron boundaries, and programs based on the method of images are used to simulate circular iron boundaries. A single procedure or program for dealing with an arbitrary iron boundary would be useful. The present program has been tested with r… more
Date: January 1, 1991
Creator: Morgan, G. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Specifications for the development of a fully three-dimensional numerical groundwater model for regional mass transport of radionuclides from a deep waste repository

Description: Specifications are given which are necessary to develop a three-dimensional numerical model capable of simulating regional mass transport of radionuclides from a deep waste repository. The model to be developed will include all of the significant mass transport processes including flow, chemical, and thermal advection, mechanical dispersion, molecular diffusion, ion exchange reactions, and radioactive decay. The model specifications also include that density and viscosity fluid properties be fu… more
Date: April 1, 1980
Creator: Prickett, T.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Conversion and improvement of the Rutherford Laboratory's magnetostatic computer code GFUN3D to the NMFECC CDC 7600

Description: The implementation of a version of the Rutherford Laboratory's magnetostatic computer code GFUN3D on the CDC 7600 at the National Magnetic Fusion Energy Computer Center is reported. A new iteration technique that greatly increases the probability of convergence and reduces computation time by about 30% for calculations with nonlinear, ferromagnetic materials is included. The use of GFUN3D on the NMFE network is discussed, and suggestions for future work are presented. Appendix A consists of rev… more
Date: June 1, 1980
Creator: Tucker, T.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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