TY - GEN
T1 - MULTISCALE ANALYSES OF FLOW IN A 5X5 ROD BUNDLE
T2 - 5th International Topical Meeting on Advances in Thermal Hydraulics 2022, ATH 2022, held in conjunction with the 2022 American Nuclear Society ,ANS Annual Meeting
AU - Kraus, Adam R.
AU - Merzari, Elia
N1 - Publisher Copyright:
© 2022 ATH. All Rights Reserved.
PY - 2022
Y1 - 2022
N2 - The fast and accurate evaluation of flow and heat transfer phenomena in rod bundles has been of longstanding interest in nuclear engineering. Computational Fluid Dynamics (CFD) can provide accurate but relatively expensive estimates, such that simulations of very long transients and high spatial detail are precluded. On the other hand, subchannel codes are relatively fast and can provide pin-level estimates, but have substantial empiricism in evaluating aspects such as crossflows and turbulent mixing coefficients. A multiscale method for bridging this knowledge/speed gap, based on the Subchannel CFD (”SubChCFD”) method of Liu et al. [1], is demonstrated here for a 5x5 square rod bundle geometry. The method is implemented in the commercial code Star-CCM+, and benchmarked against Liu's data. The geometry was chosen in part due to the availability of DNS data at relevant Reynolds number of a similar configuration for comparison. The SubChCFD results are variously compared against results from DNS, LES, wall-resolved RANS, coarse CFD, and subchannel methods. As an example of the flexibility of the SubChCFD approach, the”Hi2Lo” approach is demonstrated by using the DNS data as a correction to the original friction factor correlations in the SubChCFD. These are verified to improve the predictions. The potential of SubChCFD for modeling the narrow gap instability is also assessed. Extensions of the method, including for wire-wrapped rod bundle geometries, are discussed. Future work will implement the method into Pronghorn, with a unified pipeline via the Cardinal wrapper between the codes NekRS, Pronghorn, and BISON, to solve fuel performance problems.
AB - The fast and accurate evaluation of flow and heat transfer phenomena in rod bundles has been of longstanding interest in nuclear engineering. Computational Fluid Dynamics (CFD) can provide accurate but relatively expensive estimates, such that simulations of very long transients and high spatial detail are precluded. On the other hand, subchannel codes are relatively fast and can provide pin-level estimates, but have substantial empiricism in evaluating aspects such as crossflows and turbulent mixing coefficients. A multiscale method for bridging this knowledge/speed gap, based on the Subchannel CFD (”SubChCFD”) method of Liu et al. [1], is demonstrated here for a 5x5 square rod bundle geometry. The method is implemented in the commercial code Star-CCM+, and benchmarked against Liu's data. The geometry was chosen in part due to the availability of DNS data at relevant Reynolds number of a similar configuration for comparison. The SubChCFD results are variously compared against results from DNS, LES, wall-resolved RANS, coarse CFD, and subchannel methods. As an example of the flexibility of the SubChCFD approach, the”Hi2Lo” approach is demonstrated by using the DNS data as a correction to the original friction factor correlations in the SubChCFD. These are verified to improve the predictions. The potential of SubChCFD for modeling the narrow gap instability is also assessed. Extensions of the method, including for wire-wrapped rod bundle geometries, are discussed. Future work will implement the method into Pronghorn, with a unified pipeline via the Cardinal wrapper between the codes NekRS, Pronghorn, and BISON, to solve fuel performance problems.
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U2 - 10.13182/T126-38028
DO - 10.13182/T126-38028
M3 - Conference contribution
AN - SCOPUS:85202831066
T3 - Proceedings of Advances in Thermal Hydraulics, ATH 2022 - Embedded with the 2022 ANS Annual Meeting
SP - 430
EP - 444
BT - Proceedings of Advances in Thermal Hydraulics, ATH 2022 - Embedded with the 2022 ANS Annual Meeting
PB - American Nuclear Society
Y2 - 12 June 2022 through 16 June 2022
ER -