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Title: Uncollided flux techniques for arbitrary finite element meshes

Abstract

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.

Authors:
 [1];  [1];  [1];  [1];  [1]
  1. Texas A & M Univ., College Station, TX (United States)
Publication Date:
Research Org.:
Texas A & M Univ., College Station, TX (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1801088
Alternate Identifier(s):
OSTI ID: 1561374
Grant/Contract Number:  
NA0002376
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Computational Physics
Additional Journal Information:
Journal Volume: 398; Journal ID: ISSN 0021-9991
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; uncollided flux; ray tracing; arbitrary finite elements; first-collision source; radiation transport

Citation Formats

Hanuš, Milan, Harbour, Logan H., Ragusa, Jean C., Adams, Michael P., and Adams, Marvin L. Uncollided flux techniques for arbitrary finite element meshes. United States: N. p., 2019. Web. doi:10.1016/j.jcp.2019.07.046.
Hanuš, Milan, Harbour, Logan H., Ragusa, Jean C., Adams, Michael P., & Adams, Marvin L. Uncollided flux techniques for arbitrary finite element meshes. United States. https://doi.org/10.1016/j.jcp.2019.07.046
Hanuš, Milan, Harbour, Logan H., Ragusa, Jean C., Adams, Michael P., and Adams, Marvin L. Tue . "Uncollided flux techniques for arbitrary finite element meshes". United States. https://doi.org/10.1016/j.jcp.2019.07.046. https://www.osti.gov/servlets/purl/1801088.
@article{osti_1801088,
title = {Uncollided flux techniques for arbitrary finite element meshes},
author = {Hanuš, Milan and Harbour, Logan H. and Ragusa, Jean C. and Adams, Michael P. and Adams, Marvin L.},
abstractNote = {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.},
doi = {10.1016/j.jcp.2019.07.046},
journal = {Journal of Computational Physics},
number = ,
volume = 398,
place = {United States},
year = {Tue Aug 06 00:00:00 EDT 2019},
month = {Tue Aug 06 00:00:00 EDT 2019}
}

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Cited by: 5 works
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