Flow separation at inlet causing transition and intermittency in circular pipe flow

Ogawa, Masuro*

JAEA-Technology 2019-010, 22 Pages, 2019/07

JAEA-Technology-2019-010.pdf:1.5MB

Transition phenomena from laminar to turbulent flow are roughly classified into three categories. Circular pipe flow of the third category is linearly stable against any small disturbance, despite that flow actually transitions and transitional flow exhibits intermittency. These are among major challenges that are yet to be resolved in fluid dynamics. Thus, author proposes hypothesis as follows; "Flow in a circular pipe transitions from laminar flow because of vortices released from separation bubble forming in vicinity of inlet of pipe, and transitional flow becomes intermittent because vortex-shedding is intermittent." Present hypothesis can easily explain why linear stability theory has not been able to predict transition in circular pipe flow, why circular pipe flow actually transitions, why transitional flow actually exhibits intermittency even due to small disturbance, and why numerical analysis has not been able to predict intermittency of transitional flow in circular pipe.

Carbon-14 in neutron-irradiated graphite for graphite-moderated reactors (Joint research)

Fujii, Kimio; Matsuo, Hideto*

JAERI-Review 2002-034, 44 Pages, 2002/12

JAERI-Review-2002-034.pdf:3.34MB

Graphite material is used as a moderator and reflector of graphite-moderated gas-cooled reactors such as the Tokai Nuclear Power Station of Japan Atomic Power Company. For the decommissioning of those reactors, it is very important to obtain the density of carbon-14 in the graphite of which half-time is very long, and the development of the reduction technique for density of carbon-14 is one of the main technical issues as well. The reactor ceased the commercial operation on March 1998, and is in the process of the decommissioning. Technical developement on nuclear graphite disposal is one of the main issues, and it is pointed out that carbon-14 density is an impotant factor for the treatment on the disposal of the nuclear graphite. In order to resolve the problem, literatures survey was carried out for describing the status of technical development on resolving the problem. This report describes the outline of the literatures surveyed and the list of the related literatures is attached as well.

Hydrogen separation in H-HO-HI gaseous mixture using the silica membrance prepared by chemical vapor deposition

Hwang, G.*; Onuki, Kaoru; Shimizu, Saburo; *

J. Membr. Sci., 162(1-2), p.83 - 90, 1999/00

https://doi.org/10.1016/S0376-7388(99)00125-8

no abstracts in English

Studies on hydrogen separation membrane for IS process; Membrane preparation with porous -alumina tube

Hwang, G.*; Onuki, Kaoru; Shimizu, Saburo

JAERI-Research 98-002, 8 Pages, 1998/01

JAERI-Research-98-002.pdf:0.53MB

no abstracts in English

Study on methane separation from steam reforming product gas with polyimide membrane

*; Inagaki, Yoshiyuki; ; Sekita, Kenji; Haga, Katsuhiro; Hino, Ryutaro

JAERI-Research 97-076, 33 Pages, 1997/10

JAERI-Research-97-076.pdf:1.3MB

no abstracts in English

Preparation of gas chromatographic column for separation of hydrogen isotopes and its application to analysis in commercially available tritium gas

Saeki, Masakatsu; Hirabayashi, Takakuni; ; *; Tachikawa, Enzo

Journal of Nuclear Science and Technology, 20(9), p.762 - 768, 1983/00

https://doi.org/10.3327/jnst.20.762

no abstracts in English