An extended step characteristic method for solving the transport equation in general geometries

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Nuclear Science and Engineering; (United States)

OSTI ID:6847741

DeHart, M D; Pevey, R E ^[1]; Parish, T A ^[2]

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1. Westinghouse Savannah River Co., Aiken, SC (United States)
2. Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering

A method for applying the discrete ordinates method to solve the Boltzmann transport equation on arbitrary two-dimensional meshes has been developed. The finite difference approach normally used to approximate spatial derivatives in extrapolating angular fluxes across a cell is replaced by direct solution of the characteristic form of the transport equation for each discrete direction. Thus, computational cells are not restricted to the geometrical shape of a mesh element characteristic of a given coordinate system. However, in terms of the treatment of energy and angular dependencies, this method resembles traditional discrete ordinates techniques. By using the method developed here, a general two-dimensional space can be approximated by an irregular mesh comprised of arbitrary polygons. Results for a number of test problems have been compared with solutions obtained from traditional methods, with good agreement. Comparisons include benchmarks against analytical results for problems with simple geometry, as well as numerical results obtained from traditional discrete ordinates methods by applying the ANISN and TWOTRAN-II computer programs.

• DOE Contract Number: AC09-89SR18035
• OSTI ID: 6847741
• Journal Information: Nuclear Science and Engineering; (United States), Journal Name: Nuclear Science and Engineering; (United States) Vol. 118:2; ISSN NSENAO; ISSN 0029-5639
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100 -- Nuclear Reactor Technology-- Theory & Calculation
663610* -- Neutron Physics-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
A CODES
BOLTZMANN EQUATION
CALCULATION METHODS
COMPUTER CODES
DIFFERENTIAL EQUATIONS
DISCRETE ORDINATE METHOD
EQUATIONS
FINITE DIFFERENCE METHOD
ITERATIVE METHODS
KINETICS
MESH GENERATION
NEUTRON TRANSPORT THEORY
NUMERICAL SOLUTION
PARTIAL DIFFERENTIAL EQUATIONS
REACTOR KINETICS
T CODES
TRANSPORT THEORY