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Title: Improved discrete ordinates calculations for an approximate model of neutral particle transport in ducts

Abstract

An improved implementation of the discrete ordinates method for computing neutral particle transport in ducts is presented. The considered one-dimensional model makes use of two basic functions to represent the transverse and azimuthal dependencies of the particle angular flux in the duct. It is shown that if the problem is decomposed into uncollided and collided problems prior to using the discrete ordinates approximation, the number of ordinates necessary to achieve a desired degree of accuracy in the solution can be greatly reduced, especially for long ducts with significant wall absorption. Further savings in computer time can be attained by employing a composite quadrature based on a (nonstandard) half-range quadrature that can be generated in an effective and efficient way with one of the classical methods in the constructive theory of orthogonal polynomials.

Authors:
;  [1]
  1. Centro Tecnico Aeroespacial, Sao Jose dos Campos, Sao Paulo (Brazil). Inst. de Estudos Avancados
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
687541
Resource Type:
Journal Article
Journal Name:
Nuclear Science and Engineering
Additional Journal Information:
Journal Volume: 133; Journal Issue: 1; Other Information: PBD: Sep 1999
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; DISCRETE ORDINATE METHOD; NEUTRAL-PARTICLE TRANSPORT; DUCTS; ONE-DIMENSIONAL CALCULATIONS; QUADRATURES; PERFORMANCE

Citation Formats

Garcia, R.D.M., and Ono, S. Improved discrete ordinates calculations for an approximate model of neutral particle transport in ducts. United States: N. p., 1999. Web. doi:10.13182/NSE99-1.
Garcia, R.D.M., & Ono, S. Improved discrete ordinates calculations for an approximate model of neutral particle transport in ducts. United States. doi:10.13182/NSE99-1.
Garcia, R.D.M., and Ono, S. Wed . "Improved discrete ordinates calculations for an approximate model of neutral particle transport in ducts". United States. doi:10.13182/NSE99-1.
@article{osti_687541,
title = {Improved discrete ordinates calculations for an approximate model of neutral particle transport in ducts},
author = {Garcia, R.D.M. and Ono, S.},
abstractNote = {An improved implementation of the discrete ordinates method for computing neutral particle transport in ducts is presented. The considered one-dimensional model makes use of two basic functions to represent the transverse and azimuthal dependencies of the particle angular flux in the duct. It is shown that if the problem is decomposed into uncollided and collided problems prior to using the discrete ordinates approximation, the number of ordinates necessary to achieve a desired degree of accuracy in the solution can be greatly reduced, especially for long ducts with significant wall absorption. Further savings in computer time can be attained by employing a composite quadrature based on a (nonstandard) half-range quadrature that can be generated in an effective and efficient way with one of the classical methods in the constructive theory of orthogonal polynomials.},
doi = {10.13182/NSE99-1},
journal = {Nuclear Science and Engineering},
number = 1,
volume = 133,
place = {United States},
year = {1999},
month = {9}
}