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Journal Articles

Consistent robin boundary enforcement of particle method for heat transfer problem with arbitrary geometry

Wang, Z.; Duan, G.*; Matsunaga, Takuya*; Sugiyama, Tomoyuki

International Journal of Heat and Mass Transfer, 157, p.119919_1 - 119919_20, 2020/08

 Times Cited Count:1 Percentile:38.54(Thermodynamics)

Journal Articles

Establishment of reasonable 2-D model to investigate heat transfer and flow characteristics by using scale model of vessel cooling system for HTTR

Takada, Shoji; Ngarayana, I. W.*; Nakatsuru, Yukihiro*; Terada, Atsuhiko; Murakami, Kenta*; Sawa, Kazuhiro*

Mechanical Engineering Journal (Internet), 7(3), p.19-00536_1 - 19-00536_12, 2020/06

In this study reasonable 2D model was established by using FLUENT for start-up of analysis and evaluation of heat transfer flow characteristics in 1/6 scale model of VCS for HTTR. By setting up pressure vessel temperature around 200$$^{circ}$$C about relatively high ratio of heat transfer via natural convection in total heat removal around 20-30%, which is useful for code to experiment benchmark in the aspect to confirm accuracy to predict temperature distribution of components which is heated up by natural convection flow. The numerical results of upper head of pressure vessel by the $$kappa$$-$$omega$$-SST intermittency transition model, which can adequately reproduce the separation, re-adhesion and transition, reproduced the test results including temperature distribution well in contrast to those by the $$kappa$$-$$varepsilon$$ model in both cases that helium gas is evacuated or filled in the pressure vessel. It was emerged that any local hot spot did not appear on the top of upper head of pressure vessel where natural convection flow of air is separated in both cases. In addition, the plume of high temperature helium gas generated by the heating of heater was well mixed in the upper head and uniformly heated the inner surface of upper head without generating hot spots.

JAEA Reports

Report of summer holiday practical training 2018; Feasibility study on nuclear battery using HTTR core; Feasibility study for nuclear design

Ishitsuka, Etsuo; Matsunaka, Kazuaki*; Ishida, Hiroki*; Ho, H. Q.; Ishii, Toshiaki; Hamamoto, Shimpei; Takamatsu, Kuniyoshi; Kenzhina, I.*; Chikhray, Y.*; Kondo, Atsushi*; et al.

JAEA-Technology 2019-008, 12 Pages, 2019/07

JAEA-Technology-2019-008.pdf:2.37MB

As a summer holiday practical training 2018, the feasibility study for nuclear design of a nuclear battery using HTTR core was carried out. As a result, it is become clear that the continuous operations for about 30 years at 2 MW, about 25 years at 3 MW, about 18 years at 4 MW, about 15 years at 5 MW are possible. As an image of thermal design, the image of the nuclear battery consisting a cooling system with natural convection and a power generation system with no moving equipment is proposed. Further feasibility study to confirm the feasibility of nuclear battery will be carried out in training of next fiscal year.

Journal Articles

New reactor cavity cooling system (RCCS) with passive safety features; A Comparative methodology between a real RCCS and a scaled-down heat-removal test facility

Takamatsu, Kuniyoshi; Matsumoto, Tatsuya*; Morita, Koji*

Annals of Nuclear Energy, 96, p.137 - 147, 2016/10

 Times Cited Count:4 Percentile:49.49(Nuclear Science & Technology)

After Fukushima Daiichi nuclear disaster by TEPCO, a cooling system to prevent core damage became more important from the perspective of defense in depth. Therefore, a new, highly efficient RCCS with passive safety features without a requirement for electricity and mechanical drive is proposed. Employing the air as the working fluid and the ambient air as the ultimate heat sink, the new RCCS design strongly reduces the possibility of losing the heat sink for decay heat removal. The RCCS can always stably and passively remove a part of the released heat at the rated operation and the decay heat after reactor shutdown. Specifically, emergency power generators are not necessary and the decay heat can be passively removed for a long time, even forever if the heat removal capacity of the RCCS is sufficient. We can also define the experimental conditions on radiation and natural convection for the scale-down heat removal test facility.

Journal Articles

Natural convection heat transfer of high temperature gas in an annulus between two vertical concentric cylinders

Inaba, Yoshitomo; Zhang, Y.*; Takeda, Tetsuaki; Shiina, Yasuaki

Heat Transfer-Asian Research, 34(5), p.293 - 308, 2005/07

Water cooling panels have been adopted as the vessel cooling system of the HTTR to cool the reactor core indirectly by natural convection and thermal radiation. In order to investigate the heat transfer characteristics of high temperature gas in a vertical annular space between the reactor pressure vessel and cooling panels of the HTTR, we carried out experiments and numerical analyses on natural convection heat transfer coupled with thermal radiation heat transfer in an annulus between two vertical concentric cylinders with the inner cylinder heated and the outer cylinder cooled. In the present experiments, Rayleigh number based on the height of the annulus ranged from 2.0$$times$$10$$^{7}$$ to 5.4$$times$$10$$^{7}$$ for helium gas and from 1.2$$times$$10$$^{9}$$ to 3.5$$times$$10$$^{9}$$ for nitrogen gas. The numerical results were in good agreement with the experimental ones regarding the surface temperatures of the heating and cooling walls. As a result of the experiments and the numerical analyses, the heat transfer coefficient of natural convection coupled with thermal radiation was obtained.

Journal Articles

Helium-air counter flow in rectangular channels

Fumizawa, Motoo; Tanaka, Gaku*; Zhao, H.*; Hishida, Makoto*; Shiina, Yasuaki

Nippon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.313 - 322, 2004/12

This paper deals with a computer simulation of a helium-air counter flow in a rectangular channel. The inclination angle is varied from 0$$^{circ}$$(horizontal) to 90$$^{circ}$$(vertical). Velocity profiles and concentration profiles are calculated with a computer program VSOP sub-module. Following main features of the counter flow are discussed. (1) Time required to establish a quasi-steady state counter flow. (2) The relationship between the inclination angle and the flow patterns of the counter flow (3) The developing process of velocity profiles and concentration profiles (4) The relationship between the inclination angle of the channel and the velocity profiles of upwards flow and the downwards flow (5) The relationship between the concentration profile and the inclination angle (6) The relationship between the net in-flow rate and the inclination angle We compared the computed velocity profile and the net in-flow rate with experimental data. A good agreement is obtained between the calculation and the experiment.

Journal Articles

Study on natural convection heat transfer of high temperature gas in a vertical annular space of a double coaxial cylinder

Inaba, Yoshitomo; Zhang, Y.*; Takeda, Tetsuaki; Shiina, Yasuaki

Nippon Kikai Gakkai Rombunshu, B, 70(694), p.1518 - 1525, 2004/06

no abstracts in English

Journal Articles

Modeling for evaluation of debris coolability in lower plenum of reactor pressure vessel

Maruyama, Yu*; Moriyama, Kiyofumi; Nakamura, Hideo; Hirano, Masashi; Nakajima, K.*

Journal of Nuclear Science and Technology, 40(1), p.12 - 21, 2003/01

 Times Cited Count:5 Percentile:61.37(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Study on natural convection heat transfer in vertical annular space of a double coaxial cylinder

Inaba, Yoshitomo; Takeda, Tetsuaki

JAERI-Research 2000-062, 73 Pages, 2001/02

JAERI-Research-2000-062.pdf:2.83MB

no abstracts in English

Journal Articles

Validation of CAMP code for thermo-fluiddynamics of molten debris in lower Plenum

Maruyama, Yu; Moriyama, Kiyofumi; Nakamura, Hideo; Hashimoto, Kazuichiro; Hirano, Masashi; Nakajima, K.*

Proceedings of RASPLAV Seminar 2000 (CD-ROM), 8 Pages, 2000/11

no abstracts in English

Journal Articles

Visualization of simulated molten-fuel behavior in a pressure vessel lower head using high-frame-rate neutron radiography

Nakamura, Hideo; Shibamoto, Yasuteru; Anoda, Yoshinari; Kukita, Yutaka*; Mishima, Kaichiro*; Hibiki, Takashi*

Nuclear Technology, 125(2), p.213 - 224, 1999/02

 Times Cited Count:8 Percentile:44.32(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Natural convection heat transfer from a heated horizontal cylinder with microencapsulated phase-change-material slurries

Kubo, Shinji; Akino, Norio; *; *

Nippon Kikai Gakkai Rombunshu, B, 64(625), p.3013 - 3020, 1998/09

no abstracts in English

Journal Articles

Temperature distributions in a tokamak vacuum vessel of fusion reactor after the loss-of-vacuum events occurred

Takase, Kazuyuki; Kunugi, Tomoaki; ; Seki, Yasushi

Fusion Engineering and Design, 42, p.83 - 88, 1998/00

 Times Cited Count:11 Percentile:31.86(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Design and evaluation methods for a water cooling panel system for decay heat removal from a high-temperature gas-cooled reactor

Takada, Shoji; Suzuki, Kunihiro; Inagaki, Yoshiyuki; Sudo, Yukio

Heat Transfer-Jpn. Res., 26(3), p.159 - 175, 1997/00

no abstracts in English

Journal Articles

Interaction of natural convection between two heated horizontal cylinders installed alternately

*; *; Kubo, Shinji; Akino, Norio; *; Takase, Kazuyuki

Kashika Joho Gakkai-Shi, 18(68), p.1 - 8, 1997/00

no abstracts in English

Journal Articles

Three-dimensional analysis on thermo-fluiddynamics in piping with WINDFLOW

Maruyama, Yu; Igarashi, Minoru; Nakamura, Naohiko; Hidaka, Akihide; Hashimoto, Kazuichiro; Sugimoto, Jun; Nakajima, Kengo*

JAERI-memo 08-127, p.233 - 238, 1996/06

no abstracts in English

Journal Articles

Visualization of heat flux distributions using liquid-crystal thermography

Akino, Norio; Kubo, Shinji; K.-S.Choi*

Proc. of ASME Fluid Engineering Division Summer Meeting 1996 (FED-Vol. 239), 4, p.439 - 445, 1996/00

no abstracts in English

Journal Articles

COOLOD-N: A Copmupter code, for the analysis of steady-state thermal hydraulics in plate-type research reactor

Kaminaga, Masanori

RIST News, (21), p.42 - 47, 1996/00

no abstracts in English

Journal Articles

Numerical analyses of buoyancy-driven flow with properties that depend on the local temperature

*; Kunugi, Tomoaki; *

Therm. Sci. Eng., 4(3), p.17 - 25, 1996/00

no abstracts in English

Journal Articles

Core melt behaviors and thermal properties in LWR severe accident

Sugimoto, Jun; Uetsuka, Hiroshi; Hidaka, Akihide; Maruyama, Yu; Yamano, N.; Hashimoto, Kazuichiro

Thermophysical Properties 17 (17th Japan Symp. 1996), 0, p.163 - 166, 1996/00

no abstracts in English

32 (Records 1-20 displayed on this page)