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Emilio Baglietto. Acton, Michael (Michael John) Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering 2017-02-22T15:59:23Z 2017-02-22T15:59:23Z 2016 2016 http://hdl.handle.net/1721.1/107022 971119275 Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2016. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 72-76). Computational fluid dynamics is a powerful tool for the simulation of nuclear reactor coolant flows, such as in sodium fast reactors. In these reactors, the phenomenon of thermal striping -- characterized by oscillatory turbulent mixing of non-isothermal coolant flows -- has the potential to damage the structural integrity of reactor instrumentation and structural materials. At present, large eddy simulation is the only turbulence modeling approach which can sufficiently resolve and predict the mixing behavior of thermal striping, including temperature fluctuation and fluctuation frequencies. The extreme computational cost requirements of large eddy simulation application preclude the use of CFD for large engineering applications. In this work, the performance of the newly developed STRUCT hybrid turbulence model (Lenci, 2016) is evaluated on three representative test cases in comparison to traditional unsteady Reynolds-Averaged Navier-Stokes (URANS) and large eddy simulation (LES) models. Results indicate excellent potential for application of the STRUCT approach to sodium thermal striping flows. Best practice guidelines are developed and discussed. by Michael Acton. S.M. 76 pages eng Massachusetts Institute of Technology MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 Nuclear Science and Engineering. Scale adaptive turbulence modeling for in-vessel sodium thermal hydraulics Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="cdec72ad-1825-4048-857b-99ba18aed9df"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Scale adaptive turbulence modeling for in-vessel sodium thermal hydraulics</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2016</PublicationDate> <Authors> <Author> <DisplayName>Acton, Michael (Michael John)</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Nuclear Science and Engineering.</Keyword> <Abstract>Computational fluid dynamics is a powerful tool for the simulation of nuclear reactor coolant flows, such as in sodium fast reactors. In these reactors, the phenomenon of thermal striping -- characterized by oscillatory turbulent mixing of non-isothermal coolant flows -- has the potential to damage the structural integrity of reactor instrumentation and structural materials. At present, large eddy simulation is the only turbulence modeling approach which can sufficiently resolve and predict the mixing behavior of thermal striping, including temperature fluctuation and fluctuation frequencies. The extreme computational cost requirements of large eddy simulation application preclude the use of CFD for large engineering applications. In this work, the performance of the newly developed STRUCT hybrid turbulence model (Lenci, 2016) is evaluated on three representative test cases in comparison to traditional unsteady Reynolds-Averaged Navier-Stokes (URANS) and large eddy simulation (LES) models. Results indicate excellent potential for application of the STRUCT approach to sodium thermal striping flows. Best practice guidelines are developed and discussed.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>