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Ariyoshi, Gen; Obayashi, Hironari; Sasa, Toshinobu
Journal of Nuclear Science and Technology, 59(9), p.1071 - 1088, 2022/09
Times Cited Count:1 Percentile:29.26(Nuclear Science & Technology)Electromagnetic induction method is one of the effective techniques for local velocity measurement in heavy liquid metals. Ricou and Vives' probe and Von Weissenfluh's probe are famous instrumentations using a permanent magnet. However, sensitivity and measurement volume of the probes show unexpected variation since demagnetization of the magnet is occurred by temperature increase up to the Curie temperature. In this study, electromagnetic probe incorporating a miniature electromagnet was newly developed to overcome such unexpected variation. The diameter and the length of the sensor was 6 mm and 155 mm, respectively. The sensitivity and the measurement volume of the probe were assessed by measurement of local velocity of flowing mercury in a square channel. To clarify the validity for the measured velocity profiles, numerical velocity profiles were calculated and compared with experiment. And the validity for the measured velocity profiles were confirmed by calculated result.
Han, X.*; Shen, X.*; Yamamoto, Toshihiro*; Nakajima, Ken*; Sun, Haomin; Hibiki, Takashi*
International Journal of Heat and Mass Transfer, 144, p.118696_1 - 118696_19, 2019/12
Times Cited Count:15 Percentile:64.13(Thermodynamics)Ishikura, Shuichi*; Kogawa, Hiroyuki; Futakawa, Masatoshi; Kikuchi, Kenji; Hino, Ryutaro; Arakawa, Chuichi
Journal of Nuclear Materials, 318, p.113 - 121, 2003/05
Times Cited Count:12 Percentile:62.16(Materials Science, Multidisciplinary)The thermal shock stress in the mercury target vessel was analyzed: the target receives the incident proton beam at the energy of 1 MW with the pulse duration of 1ms. Negative pressure of maximal 61MPa was generated when the initial pressure of 52MPa propagated in mercury. It is expected then that the cavitation may be arisen by the negative pressure. So in order to know the cavitation behavior, the simulation study was carried out by using the equation of motion based on the bubble dynamics for a single bubble, and fundamental parameter analysis was carried out. It is found that a bubble has a potential expansion more than 1000 times with a change of the pressure at the window of the target vessel. Consequently wave propagation will be affected. Theoretical consideration was given to the wave motion of propagation in bubbly liquid. The equation of state in bubbly liquid can be approximated by the polynomial. The diameter of a bubble and the bubble volume fraction inherent in mercury can be decided if the critical pressure, the sound velocity, and resonance frequency is successfully measured by static and dynamic experiment.
Kritmaitree, P.; Akiyama, Mitsunobu*; Hino, Ryutaro; Kaminaga, Masanori; Terada, Atsuhiko*
Journal of Nuclear Science and Technology, 39(1), p.101 - 107, 2002/01
Times Cited Count:6 Percentile:39.48(Nuclear Science & Technology)The paper presents analytical results of suction process of a volumetric scroll pump, which will be developed for circulating liquid hydrogen in a cold moderator system. The multi-block grid generation approch has been applied to generate a moving boundaries computational model. The finer mesh patterns have been generated in the near-wall regions. The analysis has been carried out under liquid hydrogen flow conditions. The analytical results show that at the end of suction process the relative pressures increase significantly in a pocket while decrease continuously in another pocket. This phenomenon might damage scroll pump components if the high-pressure side is too high and/or the low-pressure side is too low until the cavitations occur. Therefore, the pockect should open to the discharge chamber before it closes and separates from the suction chamber in order to prevent the cavitations and extremely high-pressure regions.
Akino, Norio; Koyano, Kiyoshi*; Usui, Yoshiko*; Ota, Naomi*
Kashika Joho Gakkai-Shi, 21(Suppl.2), p.147 - 148, 2001/09
no abstracts in English
Saito, Yasushi*; Hibiki, Takashi*; Mishima, Kaichiro*; Tobita, Y.*; Suzuki, Toru*; Matsubayashi, Masahito
Proceedings of 9th International Symposium on Flow Visualization, p.391_1 - 391_10, 2000/00
no abstracts in English
Onuki, Akira; *; Akimoto, Hajime
Konsoryu Shimpojiumu '98 Koen Rombunshu, p.221 - 222, 1998/00
no abstracts in English
*; Tsuji, Yoshiyuki*; *; Nakamura, Hideo; ; Kukita, Yutaka
Nihon Genshiryoku Gakkai-Shi, 39(8), p.669 - 680, 1997/00
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)no abstracts in English
Onuki, Akira;
Proc. of ASME Heat Transfer and Fluids Engineering Divisions (HTD-Vol. 321,FED-Vol. 233), 0, p.473 - 478, 1995/00
no abstracts in English