TY - GEN
T1 - ON THE IMPACT OF PRANDTL NUMBER ON TEMPERATURE IN PARALLEL JET MIXING
AU - Acierno, John
AU - Merzari, Elia
N1 - Publisher Copyright:
© 2023 Proceedings of the 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023. All rights reserved.
PY - 2023
Y1 - 2023
N2 - Sodium-cooled Fast Reactors (SFRs) have the potential to revolutionize the future of nuclear energy due to their improved efficiency and safety measures. However, thermal striping, a phenomenon caused by fluctuations in temper-ature from mixing non-isothermal coolant streams, is a potential material safety concern that stems from the use of sodium. This phenomenon can potentially cause thermal fatigue damage in reactor upper internal structures. Although common in sodium, it can be a concern in other coolants as well. To ensure safe reactor design and operation, accurate simulations of thermal striping are crucial. To develop a thermal striping model, characterizing coolant stream mixing is the first step. In this study, we model a four-parallel plane jet geometry at various Prandtl numbers to characterize non-isothermal coolant stream mixing in a simplified upper plenum environment. To achieve accurate results, we performed Large Eddy Simulations (LES) using NekRS, an open-source spectral element CFD solver. The model was previously validated against experimental data from The University of Michigan. In this study, we will compare Power Spectrum Densities (PSD) of temperature to characterize frequency-based phenomena at different Prandtl numbers. Additionally, we will present Proper Orthogonal Decomposition (POD) of each Prandtl number to discern spatial tem-perature oscillation effects. This study aims to further our understanding of thermal striping and provide a benchmark for more cost-effective models, by studying the impact of Prandtl on jet mixing.
AB - Sodium-cooled Fast Reactors (SFRs) have the potential to revolutionize the future of nuclear energy due to their improved efficiency and safety measures. However, thermal striping, a phenomenon caused by fluctuations in temper-ature from mixing non-isothermal coolant streams, is a potential material safety concern that stems from the use of sodium. This phenomenon can potentially cause thermal fatigue damage in reactor upper internal structures. Although common in sodium, it can be a concern in other coolants as well. To ensure safe reactor design and operation, accurate simulations of thermal striping are crucial. To develop a thermal striping model, characterizing coolant stream mixing is the first step. In this study, we model a four-parallel plane jet geometry at various Prandtl numbers to characterize non-isothermal coolant stream mixing in a simplified upper plenum environment. To achieve accurate results, we performed Large Eddy Simulations (LES) using NekRS, an open-source spectral element CFD solver. The model was previously validated against experimental data from The University of Michigan. In this study, we will compare Power Spectrum Densities (PSD) of temperature to characterize frequency-based phenomena at different Prandtl numbers. Additionally, we will present Proper Orthogonal Decomposition (POD) of each Prandtl number to discern spatial tem-perature oscillation effects. This study aims to further our understanding of thermal striping and provide a benchmark for more cost-effective models, by studying the impact of Prandtl on jet mixing.
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U2 - 10.13182/NURETH20-41420
DO - 10.13182/NURETH20-41420
M3 - Conference contribution
AN - SCOPUS:85202981113
T3 - Proceedings of the 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023
SP - 1332
EP - 1345
BT - Proceedings of the 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023
PB - American Nuclear Society
T2 - 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023
Y2 - 20 August 2023 through 25 August 2023
ER -