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September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Remembering ANS member Gil Brown
Brown
The nuclear community is mourning the loss of Gilbert Brown, who passed away on July 11 at the age of 77 following a battle with cancer.
Brown, an American Nuclear Society Fellow and an ANS member for nearly 50 years, joined the faculty at Lowell Technological Institute—now the University of Massachusetts–Lowell—in 1973 and remained there for the rest of his career. He eventually became director of the UMass Lowell nuclear engineering program. After his retirement, he remained an emeritus professor at the university.
Sukesh Aghara, chair of the Nuclear Engineering Department Heads Organization, noted in an email to NEDHO members and others that “Gil was a relentless advocate for nuclear energy and a deeply respected member of our professional community. He was also a kind and generous friend—and one of the reasons I ended up at UMass Lowell. He served the university with great dedication. . . . Within NEDHO, Gil was a steady presence and served for many years as our treasurer. His contributions to nuclear engineering education and to this community will be dearly missed.”
Vaibhav Khane, Mahmoud M. Taha, Gary E. Mueller, Muthanna H. Al-Dahhan
Nuclear Technology | Volume 199 | Number 1 | July 2017 | Pages 47-66
Technical Paper | doi.org/10.1080/00295450.2017.1324729
Articles are hosted by Taylor and Francis Online.
In a pebble bed reactor (PBR) core, nuclear fuel in the form of pebbles moves slowly under the influence of gravity. Due to the dynamic nature of the core, a thorough understanding about slow and dense granular flow of pebbles is required from both a reactor safety point of view and a performance evaluation point of view. In the current study, validation of discrete element method (DEM)–based simulation for the pebble flow in a PBR was carried out. Validation of DEM-based simulations necessitates validation of the employed numerical method of simulating packed structure. Hence, a parametric sensitivity study of packing interaction properties was initially conducted and also validation of the numerical method simulating packed structure at first. The parametric sensitivity analysis suggests that static friction characteristics play an important role from a packed/pebble bed structural characterization point of view. In addition, the simulated packed structure approach has shown a good agreement with the available benchmark data. Afterward, the effect of two different half-cone angles of 30 deg and 60 deg on pebble flow field in a PBR was studied by EDEMTM-based simulations. Results of streamlines, velocity radial profiles, and direct observation of discharge indicated a plug-type flow in the upper cylindrical region, whereas results indicated converging-type flow near the bottom conical region. EDEMTM results of granular flow were validated against experimental benchmark data and show a fair agreement in terms of Lagrangian trajectories and velocity profile. Therefore, this validated EDEMTM-based simulation can be used to obtain reliable results of pebble dynamics in a PBR and to enhance understanding of this phenomenon in a PBR. However, additional experimental investigations are recommended to be carried out for different sizes of test reactors, different bottom cone angles, and different sizes of pebbles to further assess DEM simulation results before using them for full-scale reactor simulations.
