2026-09-19T06:45:41Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/46658 2023-07-11 col_2142_5131 col_2142_14837 com_2142_5130 com_2142_14836 com_2142_234

coupling neutronics tight coupling thermal-hydraulics Tightly coupled neutronics and thermal-hydraulics using open-source software text Uddin, Rizwan Uddin, Rizwan Jewett, Brian F. Kozlowski, Tomasz Stubbins, James F. Wu, Hsingtzu 2014-01-16T17:57:56Z 2014-01-16T17:57:56Z 2013-12 2014-01-16T17:57:56Z 2013-12 Coupling the neutronic and thermal-hydraulic analyses of a nuclear reactor core is important because it helps identify the most relevant safety issues. Currently all coupled computations solve the same set of governing equations using different coupling methods, which can be sorted into two categories: loose coupling and tight coupling. This dissertation proposes and verifies a third coupled approach called “the Integrated Tight Coupling (ITC) method”. The mathematical equations in the nuclear fuel are rearranged to be integrated via a novel concept of group temperature. In addition, the data from the neutron cross section library can be used directly. The ITC method is implemented using two open-source codes: the DRAGON code and OpenFOAM. Additionally, a coupled computation using these two codes is new and has not been done in the past. The ITC method is verified using two 1.5-D (1-D neutronics and 2-D thermal-hydraulics) examples: a symmetric unit cell and an asymmetric unit cell. The mesh of the tightly integrated computation is 25 % and 12 % coarser than the loosely coupled one for the symmetric case and the asymmetric case, respectively. Starting from the similar initial guess, the number of iterations for the ITC method is 24 % and 14 % fewer than those for the loosely coupled computation to reach the same accuracy for the symmetric case and the asymmetric case, respectively. In addition, the ITC method is tested with different initial guesses. For all cases tested, the scheme converged to the same solution. With further improvement and additional testing, the scheme developed and tested here has the potential to be incorporated with other neutronics and thermal- hydraulics codes. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2013-09-19T13:54:40Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Wu_Hsingtzu.pdf: 2836071 bytes, checksum: 176e24282ebd4b78eace7d113c6c250c (MD5) Made available in DSpace on 2014-01-16T17:57:56Z (GMT). No. of bitstreams: 2 Hsingtzu_Wu.pdf: 2836288 bytes, checksum: 8af8c45c0c1d2c2c858866296cd689c6 (MD5) license.txt: 4058 bytes, checksum: 9667d15304bb815c5d6746fa8e1864e5 (MD5) http://hdl.handle.net/2142/46658 en Copyright 2013 Hsingtzu Wu Nuclear, Plasma, & Rad Engr 1973 Nuclear Engineering 0139 University of Illinois at Urbana-Champaign Dissertation Ph.D. PHD:Nuclear Engineering -UIUC 10KS0139PHD