19 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Finite Difference Method"  
Results: 1 - 19
open access

Variable thickness transient ground-water flow model. Volume 1. Formulation

Description: Mathematical formulation for the variable thickness transient (VTT) model of an aquifer system is presented. The basic assumptions are described. Specific data requirements for the physical parameters are discussed. The boundary definitions and solution techniques of the numerical formulation of the system of equations are presented.
Date: December 1, 1979
Creator: Reisenauer, A.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Basic theory and equations used in the two-phase multidimensional geothermal reservoir simulator, SHAFT79

Description: The algorithm of SHAFT79 is based on mass and energy balance equations for two-phase flow in a porous medium. These basic equations are formulated as Integrated Finite Difference equations. The latter formulation allows both regular and irregular discrete grid approximations of reservoir geometry. The present version of SHAFT79 solves the non-linear mass and energy equations simultaneously using an efficient linear algebra package. The computer program is being applied to a vareity of problems … more
Date: July 1, 1979
Creator: Pruess, K. & Schroeder, R.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Differencing asymptotic diffusion theory

Description: A diffusion theory is presented which extends asymptotic diffusion to non-uniform material properties. Finite difference methods for the diffusion theory naturally result in jump conditions on interfaces when appropriate.
Date: June 7, 1979
Creator: Zimmerman, G.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Stochastic ion heating by a lower hybrid wave. II

Description: The motion of an ion in a coherent lower hybrid wave (characterized by vertical bar/sub parallel/vertical bar much less than vertical bar kappa/sub perpendicular to/vertical bar and ..omega.. much greater than ..cap omega../sub i/) in a tokamak plasma is studied. For ions satisfying ..nu../sub perpendicular to/ > ..omega../kappa/sub perpendicular to/, the Lorentz force law for the ions is reduced to a set of difference equations which give the Larmor radius and phase of an ion on one cyclotron … more
Date: April 1, 1979
Creator: Karney, C.F.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Numerical model of transient two phase flow in a geothermal well

Description: The one-dimensional transient two phase flow in a geothermal well has been modeled with a finite difference approximation. The equations of mass, momentum and energy are solved using a partially implicit method. Terms that would place a severe time restriction on the calculation are solved implicitly while other terms are solved explicitly for computational ease and efficiency. The wellbore model includes heat and mass transfer and is coupled to a simple reservoir model. It is used to investiga… more
Date: July 1, 1979
Creator: Miller, C. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Eulerian formulation of fluid-structure interaction in reactor containment system

Description: This paper is concerned with an Eulerian formulation for a fluid-structure interface developed for the nonlinear fluid-structure interaction analysis encountered in the primary containment and piping components of nuclear reactors. The Eulerian finite difference methodology is chosen because of its decisive abilities in: (1) investigating material motion with large distortions, (2) treating fluid flow around internal structures having a geometrical discontinuity, (3) handling wave transients in… more
Date: January 1, 1979
Creator: Wang, C. Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Two-dimensional fluid and thermal analysis of dry porous rock reservoirs for CAES

Description: The analysis of the hydrodynamic and thermodynamic response of a Compressed Air Energy Storage (CAES) dry porous media reservoir subjected to daily air mass cycling is described. The analysis is based upon a numerical computer model that uses a finite difference method to solve the two-dimensional (r-z) conservation equations for the transport of mass, momentum, and energy in the below ground system. The investigation quantifies the behavior of those parameters that enter the model by virtue of… more
Date: September 1, 1979
Creator: Wiles, L.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Computer simulation of ductile fracture

Description: Finite difference computer simulation programs are capable of very accurate solutions to problems in plasticity with large deformations and rotation. This opens the possibility of developing models of ductile fracture by correlating experiments with equivalent computer simulations. Selected experiments were done to emphasize different aspects of the model. A difficult problem is the establishment of a fracture-size effect. This paper is a study of the strain field around notched tensile specime… more
Date: January 1, 1979
Creator: Wilkins, M. L. & Streit, R. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Studies in Semiconducting Metal Oxides in Conjunction With Silicon for Solid State Gas Sensors. Progress Report, April 1, 1977-September 30,1979

Description: A fundamental investigation of SnO/sub 2/ and ZnO thin films with emphasis on their use in solid state gas detection is discussed. Methods of thin film preparation, described here, include the chemical vapor deposition (CVD) technique for SnO/sub 2/ films and the radio frequency sputtering technique for SnO/sub 2/ and ZnO films. The use of Auger electron spectroscopy, (AES), transmission electron microscopy, (TEM) and x ray diffractometry, (XRD) in the analysis of these films is reported. Caref… more
Date: September 1, 1979
Creator: Jordan, A. G. & Advani, G. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The ANIMAL Code

Description: This report describes ANIMAL, a two-dimensional Eulerian magnetohydrodynamic computer code. ANIMAL's physical model also appears. Formulated are temporal and spatial finite-difference equations in a manner that facilitates implementation of the algorithm. Outlined are the functions of the algorithm's FORTRAN subroutines and variables.
Date: February 28, 1979
Creator: Lindemuth, I. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Calculation of explosive rock breakage: oil shale

Description: Improved efficiency in explosive rock breakage becomes increasingly important as mining costs and the need to tap underground resources continue to grow. Industry has recognized this need for many years and has done a great deal in developing new products and new blasting techniques, generally by purely empirical means. One particular application that has received added attention within the past several years, and one that lends itself to a more objective theoretical study, is explosive fractur… more
Date: January 1, 1979
Creator: Johnson, J.N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Galerkin algorithm for multidimensional plasma simulation codes. Informal report

Description: A Galerkin finite element differencing scheme has been developed for a computer simulation of plasmas. The new difference equations identically satisfy an equation of continuity. Thus, the usual current correction procedure, involving inversion of Poisson's equation, is unnecessary. The algorithm is free of many numerical Cherenkov instabilities. This differencing scheme has been implemented in CCUBE, an already existing relativistic, electromagnetic, two-dimensional PIC code in arbitrary separ… more
Date: March 1, 1979
Creator: Godfrey, B.B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Description of the three-dimensional two-phase simulator shaft78 for use in geothermal reservoir studies

Description: The algorithm of SHAFT78 is based on mass and energy-balance equations for two-phase flow in a porous medium. The basic differential equations are converted into integrated finite-difference form. This allows regular and irregular reservoir shapes to be handled with the same ease. The equations are solved semi-implicitly for discrete time steps. The present version of SHAFT78 treats the coupling between mass and energy flow in a noniterative way. Special provisions are made to compute phase tra… more
Date: January 1, 1979
Creator: Pruess, K.; Zerzan, J.M.; Schroeder, R.C. & Witherspoon, P.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Numerical method for solution of transient, homogeneous, equilibrium, two-phase flows in one space dimension. [LMFBR]

Description: A solution method is presented for transient, homogeneous, equilibrium, two-phase flows of a single-component fluid in one space dimension. The method combines a direct finite-difference procedure and the method of characteristics. The finite-difference procedure solves the interior points of the computing domain; the boundary information is provided by a separate procedure based on the characteristics theory. The solution procedure for boundary points requires information in addition to the ph… more
Date: October 1, 1979
Creator: Shin, Y.W. & Wiedermann, A.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Computer modeling of inelastic wave propagation in porous rock

Description: Computer modeling of wave propagation in porous rock has several important applications. Among them are prediction of fragmentation and permeability changes to be caused by chemical explosions used for in situ resource recovery, and the understanding of nuclear explosion effects such as seismic wave generation, containment, and site hardness. Of interest in all these applications are the distance from the source to which inelastic effects persist and the amount of porosity change within the ine… more
Date: January 3, 1979
Creator: Cheney, J. A. (Univ. of California, Davis); Schatz, J. F. & Snell, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Anisotropic constitutive equation for use in finite difference wave propagation calculations. [Incorporation into TOODY code]

Description: An anisotropic constitutive relation was incorporated into the Lagrangian finite-difference wavecode TOODY. The details of the implementation of the constitutive relation in the wavecode and an example of its use are discussed. 4 figures, 1 table.
Date: May 1, 1979
Creator: Swegle, J.W. & Hicks, D.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Method of lines approach to the numerical solution of conservation laws

Description: New explicit finite difference methods are developed for approximating the discontinuous time dependent solutions of nonlinear hyperbolic conservation laws. The analysis is based on the method of lines approach of decoupling the space and time discretizations and analyzing each independently before combining them into a composite method. Particular attention is given analyzing to high order spatial differences, artificial dissipation and the accurate approximation of boundary conditions. Both a… more
Date: January 1, 1979
Creator: Hyman, J.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Approximate inversion method for five point difference matrix equations. [LMFBR]

Description: SIMMER, a best estimate computer program for LMFBR disrupted core analysis, is being developed at the Los Alamos Scientific Laboratory. Recent fluid dynamics methods development for SIMMER was concerned with enhancing numerical stability and reducing calculational effort. One such development considered the evaluation of the pressure change and material density change distributions during a time step. The spatially uncoupled approximate solution to be iterated was replaced with a correct spatia… more
Date: January 1, 1979
Creator: Steinke, R.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen