Simulation of Single-Phase Natural Circulation within the BEPU Framework: Sketching Scaling Uncertainty Principle by Multi-Scale CFD Approaches

التفاصيل البيبلوغرافية
العنوان: Simulation of Single-Phase Natural Circulation within the BEPU Framework: Sketching Scaling Uncertainty Principle by Multi-Scale CFD Approaches
المؤلفون: Huang, Haifu, Perez, Jorge, Alpy, Nicolas, Medale, Marc
المصدر: Best Estimate Plus Uncertainty International Conference (BEPU 2024), May 2024, Lucca, Italy
سنة النشر: 2024
المجموعة: Physics (Other)
Statistics
مصطلحات موضوعية: Physics - Classical Physics, Statistics - Applications
الوصف: In order to enhance safety, nuclear reactors in the design phase consider natural circulation as a mean to remove residual power. The simulation of this passive mechanism must be qualified between the validation range and the scope of utilization (reactor case), introducing potential physical and numerical distortion effects. In this study, we simulate the flow of liquid sodium using the TrioCFD code, employing both higher-fidelity (HF) LES and lower-fidelity (LF) URANS models. We tackle respectively numerical uncertainties through the Grid Convergence Index method, and physical modelling uncertainties through the Polynomial Chaos Expansion method available on the URANIE platform. HF simulations are shown to exhibit a strong resilience to physical distortion effects, with numerical uncertainties being intricately correlated. Conversely, the LF approach, the only one applicable at the reactor scale, is likely to present a reduced predictability. If so, the HF approach should be effective in pinpointing the LF weaknesses: the concept of scaling uncertainty is inline introduced as the growth of the LF simulation uncertainty associated with distortion effects. Thus, the paper outlines that a specific methodology within the BEPU framework - leveraging both HF and LF approaches - could pragmatically enable correlating distortion effects with scaling uncertainty, thereby providing a metric principle.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2405.18108
رقم الأكسشن: edsarx.2405.18108
قاعدة البيانات: arXiv