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Katono, Kenichi*; Tamai, Hidesada*; Nagayoshi, Takuji*; Ito, Takashi*; Takase, Kazuyuki
Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 8 Pages, 2012/12
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
Proceedings of 7th International Conference on Multiphase Flow 2010 (ICMF 2010) (CD-ROM), 7 Pages, 2010/05
For the design the natural-circulation type BWR that utilizes the FSS concept, the development of a predictive model for the droplets entrained with the steam (carryover) from the free surface is indispensable. In this paper, the droplet quality was measured with a throttling calorimeter that could measure the droplet quality based on the isenthalpic process between wet and superheated steam through the throttle. The measurements were carried out under the conditions of a pressure of 1.5-2.5 MPa. The temperature of the superheated steam after passing through the throttle was confirmed to be strongly related to the quality of the wet steam. A modified model based on the measurements proved to be capable of predicting the droplet quality within the range of the database. Evaluating the droplet quality under BWR conditions validated the feasibility of the design of the natural-circulation type BWR that utilizes the FSS concept.
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
Nihon Konsoryu Gakkai Nenkai Koenkai 2009 Koen Rombunshu, P. 2, 2009/08
The characteristics of carryover from free-surface in a natural-circulation BWR are an important subject to be resolved for economic and safe design of the reactor. In this study, droplet quality of the carryover in a test section with 0.12 m in diameter was measured using throttling calorimeter with pressure ranging from 1.5-2.5 MPa. The measured droplet quality increases with decrease in distance from free-surface and with increase in vapor volumetric flux, and these trends are similar to those of previous data.
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Zhang, W.; Takase, Kazuyuki
Nihon Kikai Gakkai Rombunshu, B, 74(742), p.1278 - 1286, 2008/06
no abstracts in English
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Takase, Kazuyuki; Akimoto, Hajime
Journal of Power and Energy Systems (Internet), 2(1), p.250 - 258, 2008/00
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Takase, Kazuyuki; Akimoto, Hajime
Proceedings of 5th Joint ASME/JSME Fluids Engineering Conference (FEDSM 2007) (CD-ROM), 8 Pages, 2007/07
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Takase, Kazuyuki; Akimoto, Hajime
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Tamai, Hidesada; Takase, Kazuyuki; Akimoto, Hajime
Proceedings of 11th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-11) (CD-ROM), 15 Pages, 2005/10
no abstracts in English
Yoshida, Hiroyuki; Ose, Yasuo*; Kureta, Masatoshi*; Nagayoshi, Takuji*; Takase, Kazuyuki; Akimoto, Hajime
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(2), p.106 - 114, 2005/06
no abstracts in English
Nagayoshi, Takuji*; Yoshida, Hiroyuki; Onuki, Akira; Akimoto, Hajime
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(1), p.16 - 24, 2005/03
A detailed gas-liquid two-phase flow analysis code based on an advanced interface-tracking method has been developed. It is expected that the developed code would be able to simulate two-phase cross flow behavior within tight-lattice fuel bundles without relying on any empirical correlations. In order to verify the applicability of the code to simulate two-phase cross flow behavior in such situations, numerical analyses of 2-channel model tests were conducted to compare the air slug deformation and separation behavior caused by cross flow through a narrow interconnection between channels. Although the code underestimated the ascending velocity of the slug, the calculated slug deformation and separation behavior were shown to be quite similar to those observed by a high-speed video camera. Moreover the minimum differential pressure between the subchannels through the interconnection, causing channel-to-channel air transfer to occur could be predicted to within 20Pa. However, further studies of modeling and implementation related to the interface-channel wall interaction, such as a contact angle of a gas-liquid interface at the channel wall, are required for prediction improvements. Nevertheless, the qualitative capability of the developed code to simulate two-phase cross flow phenomena was demonstrated.
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Ose, Yasuo*; Takase, Kazuyuki; Akimoto, Hajime
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(1), p.25 - 31, 2005/03
no abstracts in English
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Tamai, Hidesada; Takase, Kazuyuki; Akimoto, Hajime
Proceedings of 4th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-4), p.264 - 269, 2004/12
no abstracts in English
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Ose, Yasuo*; Takase, Kazuyuki; Akimoto, Hajime
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(3), p.233 - 241, 2004/09
When there are no experimental data such as the reduced-moderation water reactor (RMWR), therefore, it is very difficult to obtain highly precise predictions. The RMWR core adopts a hexagonal tight lattice arrangement with about 1 mm gap between adjacent fuel rods. In the core, there is no sufficient information about the effects of the gap spacing and grid spacer configuration on the flow characteristics. Thus, we start to develop a predictable technology for thermal-hydraulic performance of RMWR core using advanced numerical simulation technology. As part of this technology development, we are developing advanced interface tracking method to improve conservation of volume of fluid. In this paper, we describe a newly developed interface tracking method and examples of the numerical results. In the present results, the error of volume conservation in the bubbly flow is within 0.6%.
Tamai, Hidesada; Nagayoshi, Takuji*; Katono, Kenichi*; Nakagawa, Masaki*; Onuki, Akira
no journal, ,
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
no journal, ,
no abstracts in English
Nakamura, Hideo; Yamamoto, Yasushi*; Yamada, Hidetomo*; Nagayoshi, Takuji*; Nishi, Yoshihisa*
no journal, ,
no abstracts in English
Yoshida, Hiroyuki; Tamai, Hidesada; Nagayoshi, Takuji*; Misawa, Takeharu; Takase, Kazuyuki; Akimoto, Hajime
no journal, ,
no abstracts in English
Yoshida, Hiroyuki; Nagayoshi, Takuji*; Takase, Kazuyuki; Akimoto, Hajime
no journal, ,
no abstracts in English
Tamai, Hidesada; Nagayoshi, Takuji; Katono, Kenichi; Ito, Takashi; Takase, Kazuyuki
no journal, ,
no abstracts in English
Aoyama, Goro*; Nagayoshi, Takuji*; Katono, Kenichi*; Baba, Atsushi*; Tamai, Hidesada; Takase, Kazuyuki
no journal, ,
no abstracts in English
