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RANDOM SOURCE ITERATION METHOD: MITIGATING THE RAY EFFECT IN THE DISCRETE ORDINATES METHOD\

delete2026-01-01
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PRE
AI
J
Jingyi Fu *
L
Lei Li
唐旻 (Min Tang)
DOI:10.1137/24M1669748delete
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Abstract

Abstract

En 中文
The commonly used velocity discretization for simulating the radiative transport equation (RTE) is the discrete ordinates method (DOM). One of the long-standing drawbacks of DOM is the phenomenon known as the ray effect. Due to the high dimensionality of the RTE, DOM results in a large algebraic system to solve. The source iteration (SI) method is the most standard iterative method for solving this system. In this paper, by introducing randomness into the SI method, we propose a novel random source iteration (RSI) method that offers a new way to mitigate the ray effect without increasing the computational cost. We have rigorously proved that RSI is unbiased with respect to the SI method and that its variance is uniformly bounded across iteration steps; thus, the convergence order with respect to the number of samples is 1/2. Furthermore, we prove that the RSI iteration process, as a Markov chain, is ergodic under mild assumptions. Numerical examples are presented to demonstrate the convergence of RSI and its effectiveness in mitigating the ray effect.
Keywords:
randomized algorithm
radiative transport equation
discrete ordinate method
source iteration method
ray effect

Journal

SIAM Journal on Numerical Analysis cover
SIAM Journal on Numerical Analysis
IF:
2.9
Papers:
29
Citations:
1.5W

Organization

S
shanghai jiao tong university
Scholars:
15.5W
Papers: 11.6W
Citations: 159