TY - GEN
T1 - A STUDY OF LAMINAR-TURBULENT TRANSITION IN ROD BUNDLES
AU - Machado, L. C.Aldeia
AU - Dutra, C. Bourdot
AU - Bistany, S. P.
AU - Merzari, E.
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 - Rod bundles play a crucial role in various nuclear reactor core designs, including light water reactors, liquid metal reactors, heavy water reactors, and some gas fast reactors.In this study, we perform a series of high-resolution Direct Numerical simulations of laminar-turbulent transition in square rod bundles.The goal is to determine the transition onset as a function of the pitch-to-diameter ratio and Reynolds number in infinite square lattices.Very long domains are investigated in a first-of-its-kind study using the GPU-based spectral element code NekRS on the supercomputer Summit.Unique to this study is an in-depth analysis of the spatially developing transition and its impact on mixing properties.We demonstrate that laminar-turbulent transition occurs even at fairly large P/D at very low Reynolds numbers and primarily through a gap instability, at least in the initial phases of the transients.Frequency analysis is also introduced.
AB - Rod bundles play a crucial role in various nuclear reactor core designs, including light water reactors, liquid metal reactors, heavy water reactors, and some gas fast reactors.In this study, we perform a series of high-resolution Direct Numerical simulations of laminar-turbulent transition in square rod bundles.The goal is to determine the transition onset as a function of the pitch-to-diameter ratio and Reynolds number in infinite square lattices.Very long domains are investigated in a first-of-its-kind study using the GPU-based spectral element code NekRS on the supercomputer Summit.Unique to this study is an in-depth analysis of the spatially developing transition and its impact on mixing properties.We demonstrate that laminar-turbulent transition occurs even at fairly large P/D at very low Reynolds numbers and primarily through a gap instability, at least in the initial phases of the transients.Frequency analysis is also introduced.
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U2 - 10.13182/NURETH20-41503
DO - 10.13182/NURETH20-41503
M3 - Conference contribution
AN - SCOPUS:85202930723
T3 - Proceedings of the 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2023
SP - 2897
EP - 2910
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 -