TY - GEN
T1 - Steady and unsteady calculations on thermal striping phenomena in triple-parallel jet
AU - Yu, Y. Q.
AU - Merzari, E.
AU - Thomas, J. W.
AU - Obabko, A.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The particular phenomena of thermal striping are encountered in liquid metal cooled fast reactors (LMFR), in which temperature fluctuation due to convective mixing between hot and cold fluids can lead to a possibility of crack initiation and propagation in the structure due to high cycle thermal fatigue. Using sodium experiments of parallel triple jets configuration performed by Japan Atomic Energy Agency (JAEA) as benchmark, numerical simulations were carried out to evaluate the temperature fluctuation characteristics in fluid and the transfer characteristics of temperature fluctuation from fluid to structure, which is important to assess the potential thermal fatigue damage. In this study, both steady (RANS) and unsteady (URANS, LES) calculations were applied to predict the temperature fluctuations of thermal striping. The verifications on mesh density and boundary conditions were carried out. The velocity, temperature and temperature fluctuation intensity distribution were compared with the experimental data. The steady calculation has limited success in predicting the thermal hydraulic characteristics of the thermal striping, highlighting the limitations of the RANS approach in unsteady heat transfer simulations. The unsteady results exhibited reasonably good agreement with experimental results for temperature fluctuation intensity, as well as the average temperature and velocity components at the measurement locations.
AB - The particular phenomena of thermal striping are encountered in liquid metal cooled fast reactors (LMFR), in which temperature fluctuation due to convective mixing between hot and cold fluids can lead to a possibility of crack initiation and propagation in the structure due to high cycle thermal fatigue. Using sodium experiments of parallel triple jets configuration performed by Japan Atomic Energy Agency (JAEA) as benchmark, numerical simulations were carried out to evaluate the temperature fluctuation characteristics in fluid and the transfer characteristics of temperature fluctuation from fluid to structure, which is important to assess the potential thermal fatigue damage. In this study, both steady (RANS) and unsteady (URANS, LES) calculations were applied to predict the temperature fluctuations of thermal striping. The verifications on mesh density and boundary conditions were carried out. The velocity, temperature and temperature fluctuation intensity distribution were compared with the experimental data. The steady calculation has limited success in predicting the thermal hydraulic characteristics of the thermal striping, highlighting the limitations of the RANS approach in unsteady heat transfer simulations. The unsteady results exhibited reasonably good agreement with experimental results for temperature fluctuation intensity, as well as the average temperature and velocity components at the measurement locations.
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M3 - Conference contribution
AN - SCOPUS:84962679014
T3 - International Topical Meeting on Nuclear Reactor Thermal Hydraulics 2015, NURETH 2015
SP - 1435
EP - 1447
BT - International Topical Meeting on Nuclear Reactor Thermal Hydraulics 2015, NURETH 2015
PB - American Nuclear Society
T2 - 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2015
Y2 - 30 August 2015 through 4 September 2015
ER -