Multiscale Capability in Rattlesnake using Contiguous Discontinuous Discretization of Self-Adjoint Angular Flux Equation

Technical Report · Thu Sep 01 04:00:00 EDT 2016

DOI:https://doi.org/10.2172/1364491· OSTI ID:1364491

Zheng, Weixiong ^[1]; Wang, Yaqi ^[2]; DeHart, Mark D. ^[2]

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1. Texas A & M Univ., College Station, TX (United States)
2. Idaho National Lab. (INL), Idaho Falls, ID (United States)

In this report, we present a new upwinding scheme for the multiscale capability in Rattlesnake, the MOOSE based radiation transport application. Comparing with the initial implementation of multiscale utilizing Lagrange multipliers to impose strong continuity of angular flux on interface of in-between subdomains, this scheme does not require the particular domain partitioning. This upwinding scheme introduces discontinuity of angular flux and resembles the classic upwinding technique developed for solving first order transport equation using discontinuous finite element method (DFEM) on the subdomain interfaces. Because this scheme restores the causality of radiation streaming on the interfaces, significant accuracy improvement can be observed with moderate increase of the degrees of freedom comparing with the continuous method over the entire solution domain. Hybrid SN-PN is implemented and tested with this upwinding scheme. Numerical results show that the angular smoothing required by Lagrange multiplier method is not necessary for the upwinding scheme.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1364491
• Report Number(s): INL/EXT--16-39793
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
COMPARATIVE EVALUATIONS
DEGREES OF FREEDOM
FINITE ELEMENT METHOD
RADIATION STREAMING
RADIATION TRANSPORT
Rattlesnake
TREAT
multiscale