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Abe, Satoshi; Okagaki, Yuria; Satou, Akira; Shibamoto, Yasuteru
Annals of Nuclear Energy, 159, p.108321_1 - 108321_12, 2021/09
Times Cited Count：3 Percentile：44.61(Nuclear Science & Technology)Wada, Yuki; Furuichi, Noriyuki*; Kusano, Eisuke*; Tsuji, Yoshiyuki*
Proceedings of 11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP-11) (Internet), 6 Pages, 2019/07
This paper reports characteristics of turbulence intensity profile obtained in high Reynolds number actual flow facility in Japan. The experiments were performed in a pipe flow with water, and the friction Reynolds number was varied up to 
= 2.0 
10
. The streamwise velocity was measured by laser Doppler velocimetry (LDV). The new procedure to correct the measurement volume effect of LDV is suggested and we discuss turbulence intensity issues such as the inner peak Reynolds number dependence and the outer logarithmic behavior, it was found that these characteristic behaviors are consistent with previous turbulence studies.
Takada, Shoji; Ngarayana, I. W.*; Nakatsuru, Yukihiro*; Terada, Atsuhiko; Murakami, Kenta*; Sawa, Kazuhiko*
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 13 Pages, 2019/05
In the loss of core cooling test using HTTR, a technical issue is to improve prediction accuracy of temperature distribution of components in vessel cooling system (VCS). An establishment of reasonable 2D model was started by using numerical code FLUENT, which was validated using the test data by 1/6 scale model of VCS for HTTR. The pressure vessel (PV) temperature was set around 200
C attributed to relatively high ratio of natural convection heat transfer around 20% in total heat removal, which is useful for code to experiment benchmark to improve prediction accuracy. It is necessary to confirm heat transfer flow characteristics around the top of PV which is heated up by natural convection flow which was considered to be affected by separation, re-adhesion and transition flow. The k-
-SST model was selected for turbulent calculation attributed to predict the effects mentioned above adequately. The numerical results using the k--SST model reproduced the temperature distribution of PV especially the top region which is considered to be affected by separation, re-adhesion and transition flow in contract to that using k-
model which does not account the effects.
Wada, Yuki; Furuichi, Noriyuki*; Kusano, Eisuke*; Tsuji, Yoshiyuki*
Proceedings of 15th International Conference on Flow Dynamics (ICFD 2018) (USB Flash Drive), p.778 - 779, 2018/11
Spatial resolution effect of LDV (Laser Doppler Velocimetry) on the time-averaged statistics is presented in high Reynolds number turbulent pipe flow. Employing PDF (Probability Density Function) of streamwise velocity, we report the study of overestimation of time-averaged statistics based on the size of measurement volume. We proposed a simple equation to estimate their spatial resolution effect. Using the proposed equation, the measurement position and the measurement volume calculated precisely based on experimental setup, it was found that the correction for spatial resolution effect is possible. Analyzing the pipe flow data measured by LDV, we estimated the expected turbulence intensity profile. The validity of the present correction method was confirmed by comparing the correction result based on the low-resolution experimental result with the high-resolution experimental result.
Furuichi, Noriyuki*; Terao, Yoshiya*; Wada, Yuki; Tsuji, Yoshiyuki*
Physics of Fluids, 30(5), p.055101_1 - 055101_7, 2018/05
Times Cited Count：16 Percentile：72.47(Mechanics)Takase, Kazuyuki
Proceedings of OECD/NEA & IAEA Workshop on Application of CFD/CMFD Codes to Nuclear Reactor Safety and Design and their Experimental Validation (CFD4NRS-5) (Internet), 11 Pages, 2014/09
When devising the thermal design of supercritical water reactors, it is necessary to develop an analysis method that correctly predicts the turbulent heat transfer characteristics in subchannels of fuel bundles. Spacers are set into the subchannels to maintain the distances between adjacent fuel rods. The turbulent heat transfer is generally enhanced by the spacers' reduction of the cross-sectional area in the subchannels. However, since the thermophysical properties of supercritical fluids drastically change in the vicinity of a pseudocritical point, the enhancement of the turbulent heat transfer depends on the thermal design. To this end, the Japan Atomic Energy Agency is developing an analysis method that will predict the thermal-hydraulic characteristics of supercritical fluids. The heat transfer calculations were performed using a newly developed code under conditions of a subchannel with a spacer. The enhancement of the turbulent heat transfer coefficient in the subchannels with spacers was analyzed numerically.
Matsumoto, Taro; Kishimoto, Yasuaki; Miyato, Naoaki; Li, J.*
Journal of Plasma Physics, 72(6), p.1183 - 1187, 2006/12
Times Cited Count：6 Percentile：21.49(Physics, Fluids & Plasmas)no abstracts in English
Matsumoto, Taro; Kishimoto, Yasuaki; Li, J.*
Denki Gakkai Purazuma Kenkyukai Shiryo (PST-05-17), p.83 - 86, 2005/03
no abstracts in English
Satake, Shinichi*; Kunugi, Tomoaki*; Naito, Norihito*; Takase, Kazuyuki; Ose, Yasuo*
Dai-18-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu (CD-ROM), 4 Pages, 2004/12
no abstracts in English
Ida, Masato; Taniguchi, Nobuyuki*
Nihon Ryutai Rikigakkai Nenkai 2004 Koen Rombunshu, p.122 - 123, 2004/08
The numerical stability of the Gaussian filtered Navier-Stokes equations is studied theoretically. Our recent theoretical results showed that for a large filter width, the linear shears in the time-averaged velocity fields numerically destabilize the fluctuation components because a numerically unstable term is derived by the Gaussian filtering operation. In this report we extend that numerical stability analysis based on an exact expansion series for the subgrid-scale stress terms and a numerical stability analysis of arbitrary-order spatial derivatives. The present investigation shows that numerically unstable terms can appear in many situations.
Matsumoto, Taro; Kishimoto, Yasuaki; Li, J.
Journal of Plasma and Fusion Research SERIES, Vol.6, p.597 - 600, 2004/00
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*; Tamai, Hidesada; Akimoto, Hajime
Dai-22-Kai Nihon Shimyureshon Gakkai Taikai Happyo Rombunshu, p.85 - 88, 2003/06
no abstracts in English
Kishimoto, Yasuaki
Shimyureshon, 22(2), p.89 - 97, 2003/06
This is a collection of review article related to the "Multiple Time and Spatial Scale Plasma Simulation" of various fields including fundamental research area of self-organization, magnetic and laser fusion field, space and astrophysics field where a plasma plays an essential roles.
Li, J.; Kishimoto, Yasuaki
Physics of Plasmas, 10(3), p.683 - 688, 2003/03
Times Cited Count：15 Percentile：41.51(Physics, Fluids & Plasmas)Interaction between large-scale turbulence and small-scale sheared flows isa new issue in magnetized plasmas. In this work, the key interactionmechanism is explored by sampling the large-scale ion temperature gradient (ITG) mode and the small-scale zonal flows driven by the electron temperature gradient (ETG) turbulence. It is analytically found that the small-scale zonal flows lead to a radially non-local mode coupling of ITG fluctuations.
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Nihon Kikai Gakkai 2003-Nendo Nenji Taikai Koen Rombunshu, Vol.6, p.205 - 206, 2003/00
no abstracts in English
Sato, Hiroshi; Aso, Tomokazu; Kogawa, Hiroyuki; Hino, Ryutaro
Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2003) Koen Rombunshu (No.030-3), p.47 - 48, 2003/00
no abstracts in English
Takase, Kazuyuki; Kitamura, Tatsuaki*; Kume, Etsuo; Ichimiya, Koichi*; Komada, Ichiro*
Nihon Kikai Gakkai Kanto Shibu Yamanashi Koenkai (2003) Koen Rombunshu, No.030-4, p.77 - 78, 2003/00
no abstracts in English
Takase, Kazuyuki
Proceedings of the 1st International Symposium on Advanced Fluid Information (AFI-2001), p.376 - 381, 2001/10
no abstracts in English
Aso, Tomokazu; Terada, Atsuhiko*; Kaminaga, Masanori; Hino, Ryutaro
Kashika Joho Gakkai-Shi, 21(Suppl.2), p.119 - 122, 2001/09
no abstracts in English
Islam, M. S.*; Terada, Atsuhiko*; Kinoshita, Hidetaka; Hino, Ryutaro; Monde, Masanori*
JAERI-Tech 2001-044, 49 Pages, 2001/07
JAERI-Tech-2001-044.pdf:2.49MB
no abstracts in English
