标题： 在核反应堆严重事故平台中求解集中参数模型的耦合问题 显示英文标题

标题： Solving coupled problems of lumped parameter models in a platform for severe accidents in nuclear reactors

摘要： 本文专注于解决集中参数模型的耦合问题。 此类问题对于核反应堆严重事故的模拟具有重要意义：这些粗粒度模型允许快速计算，用于风险评估的统计分析以及在考虑整个严重事故情景时解决大规模问题。 然而，这种建模方法存在若干数值缺陷。 此外，在工业背景下，计算效率非常重要，这导致了各种数值约束。 本研究的目标是分析显式耦合策略在解决此类耦合问题中的适用性，并设计允许稳定和精确计算的隐式耦合方案。 所提出的方案在CEA的procor平台上进行了理论分析和测试，该平台针对使用耦合集中参数模型和耦合1D模型求解的热传导问题进行测试。 数值结果被讨论，并使我们能够强调使用设计的耦合方案而不是通常的显式耦合方案的优势。 显示英文摘要

摘要： This paper focuses on solving coupled problems of lumped parameter models. Such problems are of interest for the simulation of severe accidents in nuclear reactors~: these coarse-grained models allow for fast calculations for statistical analysis used for risk assessment and solutions of large problems when considering the whole severe accident scenario. However, this modeling approach has several numerical flaws. Besides, in this industrial context, computational efficiency is of great importance leading to various numerical constraints. The objective of this research is to analyze the applicability of explicit coupling strategies to solve such coupled problems and to design implicit coupling schemes allowing stable and accurate computations. The proposed schemes are theoretically analyzed and tested within CEA's procor platform on a problem of heat conduction solved with coupled lumped parameter models and coupled 1D models. Numerical results are discussed and allow us to emphasize the benefits of using the designed coupling schemes instead of the usual explicit coupling schemes.