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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Xia Wang, Xiaodong Sun
Nuclear Technology | Volume 167 | Number 1 | July 2009 | Pages 71-82
Technical Paper | NURETH-12 / Thermal Hydraulics | doi.org/10.13182/NT09-A8852
Articles are hosted by Taylor and Francis Online.
In the study of gas-liquid two-phase flows, one challenge is to describe the dynamic changes in flow structure, which can be considerably affected by bubble coalescence and/or disintegration in addition to bubble nucleation and condensation processes. The interfacial structure, to a first-order approximation, may be characterized by the void fraction and a geometric parameter named "interfacial area concentration," the evolution of which can be modeled by an interfacial area transport equation (IATE). A one-group IATE has been developed for bubbly flows in the literature, accounting for three dominant mechanisms: coalescence of bubbles due to random bubble collisions driven by turbulence, coalescence of bubbles due to wake entrainment, and disintegration of bubbles caused by turbulent-eddy impact. The current study is aimed at examining the capability of a computational fluid dynamics code, namely, FLUENT, with the one-group IATE implemented, in predicting two-phase-flow phase distributions. Simulations using the Eulerian multiphase model in FLUENT 6.2.16 have been performed for adiabatic upward bubbly flows in a pipe of 50.8-mm inner diameter with a range of void fractions from 4.9 to 23.1%. The predicted phase distributions yield satisfactory agreement with available experimental data, demonstrating that FLUENT with the IATE can provide a valuable simulation tool for two-phase bubbly flows.
