skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Uncollided flux techniques for arbitrary finite element meshes

Journal Article · · Journal of Computational Physics
 [1];  [1];  [1];  [1];  [1]
  1. Texas A & M Univ., College Station, TX (United States)
+ Show Author Affiliations

The uncollided angular flux can be difficult to compute accurately in discrete-ordinate radiation transport codes, especially in weakly-scattering configurations with localized sources. It has long been recognized that an analytical or semi-analytical treatment of the uncollided flux, coupled with a discrete-ordinate solution for the collided flux, can yield dramatic improvements in solution accuracy and computational efficiency. In this paper, we present such an algorithm for the semi-analytical calculation of the uncollided flux. This algorithm is unique in several aspects: (1) it applies to arbitrary polyhedral cells (and can be thus coupled with collided flux solvers that support arbitrary polyhedral meshes without the need for explicit tetrahedral re-meshing), (2) it provides accurate uncollided solutions near sources, (3) it is devised with parallel implementation in mind, and (4) it minimizes the total number of traced rays and maintains a reasonable ray density on each local subdomain. This paper provides a complete derivation of the algorithm and demonstrates its important features on a set of simple examples and a standard transport benchmark. Assessment of its parallel performance will be the subject of a subsequent paper.

Research Organization:
Texas A & M Univ., College Station, TX (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
NA0002376
OSTI ID:
1801088
Alternate ID(s):
OSTI ID: 1561374
Journal Information:
Journal of Computational Physics, Vol. 398; ISSN 0021-9991
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

References (16)

The Solid Angle of a Plane Triangle journal February 1983
A numerical algorithm for the construction of efficient quadrature rules in two and higher dimensions journal January 2010
Fast Ray-Tetrahedron Intersection Using Plucker Coordinates journal January 2003
FNSUNCL3: First Collision Source Code for TORT journal March 2000
Fast, Minimum Storage Ray-Triangle Intersection journal January 1997
Gmsh: A 3-D finite element mesh generator with built-in pre- and post-processing facilities journal September 2009
Discontinuous finite element solution of the radiation diffusion equation on arbitrary polygonal meshes and locally adapted quadrilateral grids journal January 2015
AETIUS solutions for Kobayashi 3D benchmarks with the first collision source method on the volume source and unstructured tetrahedral mesh journal March 2018
Quadratic serendipity discontinuous finite element discretization for S transport on arbitrary polygonal grids journal December 2018
Denovo: A New Three-Dimensional Parallel Discrete Ordinates Code in SCALE journal August 2010
TORT solutions with FNSUNCL3 for Kobayashi's 3D benchmarks journal January 2001
TetGen, a Delaunay-Based Quality Tetrahedral Mesh Generator journal February 2015
3D radiation transport benchmark problems and results for simple geometries with void region journal January 2001
Ray-Effect Mitigation Methods for Two-Dimensional Neutron Transport Theory journal March 1977
On the singular structure of the uncollided and first-collided components of the Green's function journal September 2000
A robust segment/triangle intersection algorithm for interference tests. Efficiency study journal July 2010

Similar Records

Related Subjects

42 ENGINEERING
uncollided flux
ray tracing
arbitrary finite elements
first-collision source
radiation transport