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Han, X.*; Shen, X.*; Yamamoto, Toshihiro*; Nakajima, Ken*; Sun, Haomin; Hibiki, Takashi*
International Journal of Heat and Mass Transfer, 178, p.121637_1 - 121637_24, 2021/10
Times Cited Count:7 Percentile:57.51(Thermodynamics)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)Xiao, Y.*; Shen, X.*; Miwa, Shuichiro*; Sun, Haomin; Hibiki, Takashi*
Konsoryu Shimpojiumu 2018 Koen Rombunshu (Internet), 2 Pages, 2018/08
In order to develop constitutive equations of two-fluid model in rod bundle flow channels, experiments of adiabatic air-water upward two-phase flow in 66 rod bundle flow channel were performed. Local flow parameters such as void fraction, interfacial area concentration (IAC) and so on were measured by a double-sensor optical probe. The area-averaged void fraction and IAC data were compared with the predictions from a drift-flux model and an IAC correlation.
Shen, X.*; Schlegel, J. P.*; Hibiki, Takashi*; Nakamura, Hideo
Proceedings of 2017 Japan-US Seminar on Two-Phase Flow Dynamics (JUS 2017), 6 Pages, 2017/06
Onuki, Akira; Akimoto, Hajime
Proceedings of the 8th International Symposium on Flow Modeling and Turbulence Measurements (FMTM2001) (CD-ROM), 7 Pages, 2001/12
Multi-dimensional analyses have been expected with expanding computation resources for gas-liquid two-phase flow. We recently developed models for bubble turbulent diffusion and bubble diameter to predict the phase distribution by a multi-dimensional two-fluid model. This study was performed to verify our model. The verification was performed using databases under diameter; 9 mm to 155 mm, pressure; atmospheric to 4.9 MPa, flow rate; superficial gas velocity = 0.01 to 5.5 m/s and superficial liquid one = 0.0 to 4.3 m/s, fluid combination; air-water or steam-water. Through the assessments, our model was found to be applicable to the wide range of flow conditions including the effect of pipe diameter. The shape of phase distribution and the average void fraction are predicted well qualitatively and quantitatively. Since the model is established using the ratio of bubble diameter to eddy size as a key-parameter, the ratio is one of important parameters to develop the constitutive equations in the multi-dimensional two-fluid model.
Onuki, Akira; Akamatsu, Mikio*; Akimoto, Hajime
Nihon Konsoryu Gakkai Dai-5-Kai Oganaizudo Konsoryu Foramu Hobunshu, p.87 - 92, 2001/09
Multi-dimensional analyses have been expected with expanding computation resources for gas-liquid two-phase flow in a complex geometry such as fuel rod bundles. Japan Atomic Energy Research Institute is developing a numerical analytical method for the geometry effect, which is based on three-dimensional two-fluid model. In this study, a general curvilinear coordinate system was introduced to the two-fluid model code ACE-3D and air-water two-phase flow around a circular cylinder was analyzed. The present method predicts an air concentration to vortex regions behind the cylinder and a temporal fluctuation of vortex intensity; these two phenomena have been observed in experiments. It is clarified that the phenomena depend on a relative relationship between the drag force and the inertia of bubbles due to pressure fields.
Onuki, Akira; Akimoto, Hajime
International Journal of Multiphase Flow, 26(3), p.367 - 386, 2000/03
Times Cited Count:131 Percentile:96(Mechanics)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
Mishima, Kaichiro*; Hibiki, Takashi*; Saito, Y.*; Nishihara, Hideaki*; Tobita, Y.*; *; Matsubayashi, Masahito
Nuclear Instruments and Methods in Physics Research A, 424(1), p.229 - 234, 1999/00
Times Cited Count:31 Percentile:88.42(Instruments & Instrumentation)no abstracts in English
Onuki, Akira; Kamo, Hideki*; Akimoto, Hajime
Eighth Int. Topical Meeting on Nuclear Reactor Thermal-Hydraulics (NURETH-8), 3, p.1670 - 1676, 1997/00
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;
Int. J. Multiph. Flow, 22(6), p.1143 - 1154, 1996/00
Times Cited Count:41 Percentile:83.45(Mechanics)no abstracts in English
Ote, Naosuke*; Koizumi, Yasuo*; Kamide, Hideki; Ohno, Shuji; Ito, Kei
no journal, ,
A sodium-cooled fast breeder reactor is now at the development stage in Japan. One concern for safety is cover gas entrainment into the sodium coolant. The gas entrainment rate into liquid by the vortex formed on the free surface was examined experimentally. Liquid flowed into a cylindrical vessel from a wall tangentially. Swirl flow was formed in the vessel, and then liquid drained from the bottom outlet of the vessel. A hollow vortex was formed on the free surface in the test vessel. The air was entrained under the free surface of the vortex and carried away from the bottom of the vessel. The flow state of the gas entertainment was visually observed by using a high speed video camera. The gas entrainment rate into liquid was measured. In the previous study, test fluid was water. Kerosene and 20 cSt silicone oil were newly introduced as the test fluid to examine the effect of the physical properties on the gas entertainment phenomena.