Development of prediction technology of two-phase flow dynamics under earthquake acceleration, 16; Experimental and numerical study of pressure fluctuation effects on bubble motion

Kato, Yuki; Yoshida, Hiroyuki; Yokoyama, Ryotaro*; Kanagawa, Tetsuya*; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05

Development of prediction technology of two-phase flow dynamics under earthquake acceleration, 14; Numerical simulation of two-phase flow in subchannels under accelerating condition

Yoshida, Hiroyuki; Nagatake, Taku; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Proceedings of 22nd International Conference on Nuclear Engineering (ICONE-22) (DVD-ROM), 10 Pages, 2014/07

https://doi.org/10.1115/ICONE22-30153

Numerical simulation of rising bubble behavior under accelerating conditions

Yoshida, Hiroyuki; Nagatake, Taku; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Dai-62-Kai Riron Oyo Rikigaku Koenkai Koen Rombunshu (USB Flash Drive), 2 Pages, 2013/03

https://www.jstage.jst.go.jp/article/japannctam/62/0/62_54/_article/-char/ja/

no abstracts in English

Numerical prediction of two-phase flow behavior under seismic condition by use of interface tracking method

Yoshida, Hiroyuki; Nagatake, Taku; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 9 Pages, 2012/12

Investigation on fluid-structure thermal interaction related to Eddy structure on branch jet in T-junction

Tanaka, Masaaki; Takita, Hiroki*; Monji, Hideaki*; Ohshima, Hiroyuki

Nihon Kikai Gakkai Rombunshu, B, 78(792), p.1462 - 1465, 2012/08

https://doi.org/10.1299/kikaib.78.1462

Water experiment and numerical simulation under thermal interaction conditions between fluid and structure were conducted for a T-junction piping system. In the experiment, temperatures at 2 mm from the wall in fluid, on the wall and at 3 mm inside from the wall in structure along a vertical trace line were measured simultaneously. Numerical results indicated that the fluid temperature distribution near the wall was much affected by the thermal interaction with the structure and that fluid-structure thermal interaction was necessarily considered for thermal fatigue estimation in the thermal striping phenomena.

Numerical simulation of two-phase flow behavior under earthquake acceleration

Yoshida, Hiroyuki; Takase, Kazuyuki; Kaneko, Akiko*; Monji, Hideaki*; Abe, Yutaka*

Proceedings of IEEE PES Asia-Pacific Power and Energy Engineering Conference 2012 (APPEEC 2012) (CD-ROM), 4 Pages, 2012/03

https://doi.org/10.1109/APPEEC.2012.6307082

Numerical investigation on thermal mixing related to eddy structure in T-junction

Tanaka, Masaaki; Kurokawa, Koji*; Takita, Hiroki*; Monji, Hideaki*; Ohshima, Hiroyuki

Nihon Kikai Gakkai Rombunshu, B, 77(776), p.969 - 973, 2011/04

https://doi.org/10.1299/kikaib.77.969

Numerical simulations for a T-pipe consisting of a rectangular duct for main stream and a circular pipe for branch stream were performed to investigate relation between large-scale eddy structure formation in the mixing area and temperature fluctuation generation on the wall. Moreover, the numerical simulation to investigate thermal interaction between fluid and structure were conducted. Experimental results of temperatures at 2 mm from the wall in fluid, on the wall and at 3 mm inside from the wall in structure were compared with those of the numerical results. The numerical results indicate that the fluid-structure thermal interaction is necessarily considered for thermal fatigue estimation in the thermal striping phenomena.

Improvement of gas entrainment prediction method; Introduction of surface tension effect

Ito, Kei; Sakai, Takaaki; Eguchi, Yuzuru*; Monji, Hideaki*; Ohshima, Hiroyuki; Uchibori, Akihiro; Xu, Y.*

Journal of Nuclear Science and Technology, 47(9), p.771 - 778, 2010/09

https://doi.org/10.3327/jnst.47.771

A gas entrainment (GE) prediction method has been developed to establish design criteria for the large-scale sodium-cooled fast reactor (JSFR) systems. In this paper, the evaluation accuracy of gas core lengths is improved by introducing the surface tension effects into the prototype GE prediction method. For the improvement, the mechanical balance between gravitational, centrifugal, and surface tension forces is considered. The improved GE prediction method is validated by analyzing the gas core lengths observed in simple experiments. Results show that the analytical gas core lengths calculated by the improved GE prediction method become shorter in comparison to the prototype GE prediction method, and are in good agreement with the experimental data. In addition, the experimental data under different temperature and surfactant concentration conditions are reproduced by the improved GE prediction method.

Experimental study on thermal mixing related to eddy structure in T-junction

Tanaka, Masaaki; Kurokawa, Koji*; Takita, Hiroki*; Monji, Hideaki*

Nihon Kikai Gakkai Rombunshu, B, 76(763), p.463 - 465, 2010/03

In this study, a simplified T-junction piping system consisting of a rectangular duct for main stream and a circular pipe for branch stream was used as the test section in the water experiment. Time series of instantaneous two-dimensional velocity fields were obtained by PIV (Particle Image Velocimetry) in the mixing area. And fluid temperature fluctuations at several positions at 2 mm inside from the wall were also measured by thermo-couples. Focusing on the frequency characteristics, formation of eddy structure in the mixing area and mutual relation between the temperature fluctuation generation and the flow structure were discussed.

Numerical investigation of flow structure in pipe elbow with large eddy simulation approach

Tanaka, Masaaki; Ohshima, Hiroyuki; Monji, Hideaki*

Proceedings of 2009 ASME Pressure Vessels and Piping Division Conference (PVP 2009) (CD-ROM), 10 Pages, 2009/07

We have been developing a numerical simulation code "MUGTHES". MUGTHES employs large eddy simulation approach to calculate unsteady thermal-hydraulic phenomena and the boundary fitted coordinate system to model complex geometry in systems precisely. In this study, numerical simulations were conducted for pipe elbow flows in various curvature radius ratio conditions at several Reynolds number conditions. Through these simulations, applicability of MUGTHES to the elbow pipe flow was confirmed and the characteristics of three-dimensional flow structure that might influence on the structural integrity of the elbow pipe was discussed.