Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kureta, Masatoshi; Yamagata, Yoji*; Miyakoshi, Ken*; Mashii, Tatsuya*; Miura, Yoshiaki*; Takahashi, Kazunori*
JAEA-Research 2022-007, 28 Pages, 2022/09
To enhance energy separation in a counter-current Ranque-Hilsch vortex tube, a newly designed hollow helical fin was inserted into the hot tube of the vortex tube. In this study, the effect of the fin on the energy separation was investigated using three types of the vortex tube, and then computational fluid dynamics (CFD) simulation has been conducted to understand the experimental results and discuss the flow structure in the vortex tube with the hollow helical fin. As a result, it was found from the experimental data that the fin effectively enhanced energy separation, and that the tube length could be shorten. When the inlet air pressure was 0.5 MPa, the maximum temperature difference from the inlet to the cold exit was 62.2C. The CFD code employing the Reynolds Stress Model (RSM) turbulence model was used to analyze the fluid dynamics in the vortex tube. As a result, it was confirmed that the temperature, velocity, and pressure distributions changed significantly at the stagnation point, and that the distributions in the tube with the fin were completely different from those without the fin. It was thought that a strong reversing helical vortex flow with small recirculating vortex structure formed between the fin end and the stagnation point on the cold exit side would enhance energy separation in the vortex tube with the hollow helical fin.
Ido, Takeshi*; Miura, Yukitoshi; Hoshino, Katsumichi; Kamiya, Kensaku; Hamada, Yasuji*; Nishizawa, Akimitsu*; Kawasumi, Yoshiaki*; Ogawa, Hiroaki; Nagashima, Yoshihiko*; Shinohara, Koji; et al.
Nuclear Fusion, 46(5), p.512 - 520, 2006/05
Times Cited Count:86 Percentile:92.82(Physics, Fluids & Plasmas)The electrostatic fluctuation spectrum and the fluctuation-induced particle flux of the JFT-2M tokamak were estimated using the hevy ion beam probe (HIBP) measurement. A geodesic acoustic mode (GAM) of the frequency about15kHz was identified in the L-mode. The GAM has its peak at about 3cm inside of the separatrix with the electric field of about 1.4kV/m. The estimated turbulent particle flux is found to be intermittent. It is found that the density fluctuation is modulated by the GAM in the wide frequency range and the coherence analysis shows that the flucruation-induced particle flux is partially contributed by the GAM. In the H-mode the GAM disappears and the fluctuation and the flux is much decreased.The mechanism of the large burst-like flux in the L-mode is not understood yet and left as the future problem.
Kasai, Satoshi*; Kamiya, Kensaku; Shinohara, Koji; Kawashima, Hisato; Ogawa, Hiroaki; Uehara, Kazuya; Miura, Yukitoshi; Okano, Fuminori; Suzuki, Sadaaki; Hoshino, Katsumichi; et al.
Fusion Science and Technology, 49(2), p.225 - 240, 2006/02
Times Cited Count:3 Percentile:24.07(Nuclear Science & Technology)The diagnostic system of JFT-2M has consisted of about 30 individual diagnostic instruments,which were used to study the plasma production, control, equilibrium, stability, confinement, plasma heating by NBI and/or RF (LH, ICRF, ECH) and current drive by RF. In these instruments, the motional Stark effect (MSE) polarimeter, charge exchanged recombination spectroscopy (CXRS), heavy-ion beam probe (HIBP), time of flight (TOF) neutral particle analyzer, etc. have contributed to make clear the improved mechanism of confinement such as H-mode and High Recycling Steady (HRS) H-mode, and to search the operational region of these modes.The infrared TV camera system and lost ion probe have played a very important role to investigate the heat load onto the walls due to ripple loss particles and escaping ions from core plasma, respectively.
Sato, Yoshihiko; Koyama, Tomozo; Miura, Akihiko; ; ; Shigetome, Yoshiaki
Proceedings of 2nd International Conference on Safewaste 2000, 0 Pages, 2000/10
On march 11,1997, bituminization demonstration facility(BDF) in Tokai Reprocessing Plant (TRP) of power reactor and nuclear fuel development corporation (PNC) made fire and explosion incident. Investigation of the cause of the fire and explosion incident at BDF was carefully conducted. The main cause of the fire is clarified to have been physical heating inside the extruder that provided unusual high temperature of bituminized product at filling. Physical feating is considered to be derived from decrease of feed rate of liquid waste to the extruder. The causes of the explosion are accumulation offlammable gas generated from insufficiently extinguished bituminized product inside the filling room of which the ventilation system was shut doen. The gas was ignited by another ignition of the heated drum.
Ido, Tsuyoshi; Kamiya, Kensaku; Miura, Yukitoshi; Hamada, Yasuji*; Nishizawa, Akimitsu*; Kawasumi, Yoshiaki*
Plasma Physics and Controlled Fusion, 42(5A), p.A309 - A315, 2000/05
Times Cited Count:18 Percentile:49.58(Physics, Fluids & Plasmas)no abstracts in English
Ido, Tsuyoshi*; Kamiya, Kensaku*; Hamada, Y.*; Nishizawa, A.*; Kawasumi, Y.*; Miura, Yukitoshi
Plasma Physics and Controlled Fusion, 41(8), p.1013 - 1024, 1999/08
Times Cited Count:10 Percentile:35.69(Physics, Fluids & Plasmas)no abstracts in English
Shigetome, Yoshiaki; ; ; Miura, Akihiko; Sato, Yoshihiko; Koyama, Tomozo
JNC TN8200 99-001, 128 Pages, 1999/07
None
Koyama, Tomozo; ; Miura, Akihiko; ; Sato, Yoshihiko; Shigetome, Yoshiaki
International workshop on the safty and perfo, 0 Pages, 1999/07
None
Ido, Tsuyoshi*; Hamada, Y.*; *; Kawasumi, Y.*; Miura, Yukitoshi; Kamiya, Kensaku*
Review of Scientific Instruments, 70(1), p.955 - 958, 1999/01
Times Cited Count:32 Percentile:84.81(Instruments & Instrumentation)no abstracts in English
Hamada, Y.*; Ido, Tsuyoshi*; Kamiya, Kensaku*; *; Kawasumi, Y.*; Miura, Yukitoshi; JFT-2M Group
IAEA-CN-69/PDP/01 (CD-ROM), 4 Pages, 1999/00
no abstracts in English
Kato, Satoshi*; Miura, Osuke*; Ito, Daisuke*; Takahashi, Yoshiaki; Wada, Yukio
no journal, ,
no abstracts in English
Miura, Katsue; Sato, Soichi; Noguchi, Shinichi; Yonekawa, Minoru; Furusho, Yoshiaki*
no journal, ,
no abstracts in English
Sato, Soichi; Iwasaki, Maho; Miura, Katsue; Furusho, Yoshiaki*; Nakayama, Shinichi
no journal, ,