Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies

Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017.

Bibliographic Details
Main Author: Everett, Patrick F
Other Authors: Emilio Baglietto.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2017
Subjects:
Online Access:http://hdl.handle.net/1721.1/112371
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author Everett, Patrick F
author2 Emilio Baglietto.
author_facet Emilio Baglietto.
Everett, Patrick F
author_sort Everett, Patrick F
collection MIT
description Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017.
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spelling mit-1721.1/1123712019-04-10T11:42:17Z Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies Everett, Patrick F Emilio Baglietto. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. Nuclear Science and Engineering. Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017. 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 24-26). The presence of quasi-periodic flow pulsations in fuel assemblies has been observed since the 1960's but is still not fully understood. Current design and licensing practices for nuclear reactor fuel mostly rely on 1-dimensional subchannel simulation tools, which might not accurately predict the increased subchannel mixing caused by flow pulsations. The present work develops a quantitative relationship between subchannel mixing and the inter-subchannel velocity gradient, shown to be the driving force of flow pulsation. A sensitivity study on rod-bundle geometry, based on an experiment by Bardet and Balaras at George Washington University, was conducted with a URANS method in transient simulations using the commercial software Star-CCM+. A linear relationship was observed between crossflow mixing and [delta]vbulk, defined as the difference in bulk velocities of adjacent subchannels. A threshold value of [delta]vbulk was seen close to 0.4 m/s, below which very little crossflow mixing was observed. Using these results, an analytical relationship between inter-subchannel velocity gradient and crossflow mixing could be developed and implemented into subchannel codes for more accurate modeling of flow in a fuel assembly. by Patrick F. Everett. S.B. 2017-12-05T16:24:58Z 2017-12-05T16:24:58Z 2017 2017 Thesis http://hdl.handle.net/1721.1/112371 1011355949 eng 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 26 pages application/pdf Massachusetts Institute of Technology
spellingShingle Nuclear Science and Engineering.
Everett, Patrick F
Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title_full Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title_fullStr Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title_full_unstemmed Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title_short Investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
title_sort investigation of velocity gradient as driving force of flow pulsation in fuel assemblies
topic Nuclear Science and Engineering.
url http://hdl.handle.net/1721.1/112371
work_keys_str_mv AT everettpatrickf investigationofvelocitygradientasdrivingforceofflowpulsationinfuelassemblies