Validation of URANS and STRUCT-ε turbulence models for stratified sodium flow

Journal Article · 07 October 2022 · Nuclear Engineering and Design

DOI: https://doi.org/10.1016/j.nucengdes.2022.112009 · OSTI ID:2424658

Wiser, Ralph ^[1]; Baglietto, Emilio  ^[1]; Schneider, James ^[2]; Anderson, Mark H.  ^[2]

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1. Massachusetts Institute of Technology (MIT), Cambridge, MA (United States)
2. University of Wisconsin, Madison, WI (United States)

Simulations of a transient stratified sodium experiment are carried out using a classic unsteady RANS model and the second-generation URANS model, STRUCT-ε. Turbulence modeling challenges and their implications to stratified flow prediction are discussed in the context of other sources of error. Input errors are discussed and addressed; discretization error is calculated to be less than 5% of the inlet velocity, for 80% of the domain; and remaining errors in temperature distributions are attributed to the turbulence model. Qualitative flow features from the simulations are presented and discussed. Compared to the experiment, the STRUCT-ε turbulence model provides a more physically accurate prediction of temperature and momentum mixing in key regions of the domain. Quantitative measures such as the L₂ norm of the temperature discrepancy demonstrate the improved performance of the STRUCT-ε approach. In conclusion, the magnitude of the temperature fluctuations is very well-predicted by the STRUCT-ε, while URANS overpredicts them by approximately 50%.

• Research Organization: Massachusetts Institute of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE
• OSTI ID: 2424658
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Vol. 399; ISSN 0029-5493
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English