FURUYA, Masahiro

写真a

Affiliation

Faculty of Science and Engineering, Graduate School of Advanced Science and Engineering

Job title

Professor(without tenure)

Homepage URL

http://kaken.nii.ac.jp/d/r/80371342.ja.html

Research Institute 【 display / non-display

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Degree 【 display / non-display

  • Delft University of Technology   Ph.D.

Research Experience 【 display / non-display

  • 2016.04
    -
    Now

    Tokyo Institute of Technology   Major in Nuclear Engineering, Department of Transdisciplinary Science and Engineering Graduate School of Environment and Society   Visiting Professor

  • 2014.07
    -
    Now

    Central Research Institute of Electric Power Industry   Nuclear Technology Research Laboratory   Deputy Associate Vice President

  • 2015.11
    -
    2016.03

    東京工業大学大学院   原子核工学専攻   連携教授

  • 2006
    -
    2008

    (財)電力中央研究所   原子力技術研究所   主任研究員

Professional Memberships 【 display / non-display

  •  
     
     

    ATOMIC ENERGY SOCIETY OF JAPAN

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    THE JAPANESE SOCIETY FOR MULTIPHASE FLOW

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    THE HEAT TRANSFER SOCIETY OF JAPAN

  •  
     
     

    THE JAPAN SOCIETY OF MECHANICAL ENGINEERS

 

Research Areas 【 display / non-display

  • Analytical chemistry

  • Energy chemistry

  • Inorganic materials and properties

  • Composite materials and interfaces

  • Fluid engineering

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Research Interests 【 display / non-display

  • 放射線誘起表面活性

  • 放射線

  • 海洋工学

  • 放射線,X線,粒子線

  • 船舶・海洋構造物

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Papers 【 display / non-display

  • Validation of droplet-generation performance of a newly developed microfluidic device with a three-dimensional structure

    Yoshito Nozaki, Dong Hyun Yoon, Masahiro Furuya, Hiroyuki Fujita, Tetsushi Sekiguchi, Shuichi Shoji

    Sensors and Actuators A: Physical   331   112917 - 112917  2021.11

     View Summary

    We fabricated a microfluidic device with a three-dimensional (3D) structure and verified its droplet-generation performance for the stable production of droplets of around 10 μm in size. We compared the performance of the 3D device with that of conventional simple T-junction and cross-junction structures. The continuous phase sheared the dispersed phase into droplets from eight directions in the 3D device, compared with only one direction in the T-junction device and two in the cross-junction device. Droplets were produced efficiently over a wide range of fluid properties and flow conditions with the 3D device, unlike with the two conventional planar devices. Fluidic experiments were conducted using mineral oil with a surfactant as the continuous phase, deionized (DI) water as the dispersed phase, and DI water with glycerin to change the viscosity of the dispersed phase. The minimum droplet length was 47.2 μm in the T-junction device, 39.0 μm in the cross-junction device, and 22.4 μm in the 3D device when using a water and glycerin mixture with a viscosity of 9.0 mPa·s. Compared with the conventional devices, smaller droplets were produced using our 3D device, indicating that it has excellent droplet-generation performance.

    DOI

  • Measurement of forced convection subcooled boiling flow and rod surface temperature distribution

    Atsushi Ui, Masahiro Furuya, Takahiro Arai, Kenetsu Shirakawa

    Nuclear Engineering and Design   381  2021.09

     View Summary

    In order to obtain high-resolution data for modelling of boiling two-phase flow and its validation, we designed and constructed a test loop with a vertical annulus flow path and conducted subcooled boiling experiments to investigate subcooled bubble incipience and its development process under atmospheric condition. Three kinds of the state-of-the art measurement techniques were applied to quantify key parameters such as radial and vertical distributions of void fraction, bubble velocity, interfacial area concentration (IAC), Sauter mean diameters, high-resolution temperature distribution on rod surface, bubble transport behavior, and turbulent velocity components as well as onset of nucleate boiling (ONB), and onset of significant void (OSV).

    DOI

  • Study on improvement for the prediction accuracy of natural circulation flow rate by investigating void fraction correlation

    Shunsuke Yoshimura, Takuma Yamaguchi, Keisuke Ino, Masahiro Furuya, Shinichi Morooka

    Nuclear Engineering and Design   380  2021.08

     View Summary

    Natural circulation is a key technology for developing the molten core cooling system without an external power source from the lessons of the severe accident at Fukushima-Daiichi Nuclear Power Station. This study is devoted to quantify the void fraction which is an important parameter for the driving force of natural circulation flow, and to evaluate the effect of the void fraction correlation on the prediction accuracy of the natural circulation flow rate. Test was conducted at atmospheric pressure and room temperature, using the upward air–water two phase flow. Vertical tubes with an inner diameter of 36 and 25 mm were used as the test section. The void fraction was measured by three different methods: quick-closing valve method, pressure drop method, and conductive void-probe method. The following conclusions are obtained from this study: (1) The data of the natural circulation flow rate, void fraction and pressure drop for the upward air–water two phase flow at atmospheric pressure and room temperature were obtained to develop and verify the new model. (2) By improving the void correlation, it was found that the prediction accuracy of the natural circulation flow rate could be improved by about 10% to 5%, that is, the prediction error can be halved in the range of this study. (3) The natural circulation flow rate for 25 mm test section was saturated with increasing the air flow rate at higher air flow condition. The model cannot predict this tendency. From the point of design of the actual molten core cooling system, the model improvements in this region are necessary in the future.

    DOI

  • Efficient Generation of Microdroplets Using Tail Breakup Induced with Multi-Branch Channels

    Daiki Tanaka, Satsuki Kajiya, Seito Shijo, Dong Hyun Yoon, Masahiro Furuya, Yoshito Nozaki, Hiroyuki Fujita, Tetsushi Sekiguchi, Shuichi Shoji

    Molecules   26 ( 12 ) 3707 - 3707  2021.06

     View Summary

    In recent years, research on the application of microdroplets in the fields of biotechnology and chemistry has made remarkable progress, but the technology for the stable generation of single-micrometer-scale microdroplets has not yet been established. In this paper, we developed an efficient and stable single-micrometer-scale droplet generation device based on the fragmentation of droplet tails, called "tail thread mode", that appears under moderate flow conditions. This method can efficiently encapsulate microbeads that mimic cells and chemical products in passively generated single-micrometer-scale microdroplets. The device has a simple 2D structure; a T-junction is used for droplet generation; and in the downstream, multi-branch channels are designed for droplet deformation into the tail. Several 1-2 mu m droplets were successfully produced by the tail's fragmentation; this continuous splitting was induced by the branch channels. We examined a wide range of experimental conditions and found the optimal flow rate condition can be reduced to one-tenth compared to the conventional tip-streaming method. A mold was fabricated by simple soft lithography, and a polydimethylsiloxane (PDMS) device was fabricated using the mold. Based on the 15 patterns of experimental conditions and the results, the key factors for the generation of microdroplets in this device were examined. In the most efficient condition, 61.1% of the total droplets generated were smaller than 2 mu m.

    DOI

  • Evaluation of structural effect of BWR spacers on droplet flow dynamics

    Riichiro Okawa, Masahiro Furuya, Takahiro Arai, Tsugumasa Iiyama

    Nuclear Engineering and Design   377  2021.06

     View Summary

    We have established an experimental system to visualize a droplet flow in a simulated BWR fuel sub-channel optically and measure the diameter and velocity of droplet after passing through a spacer. For representative spacers of ferrule and grid type, an effect of them on downstream droplets was evaluated with the experimental system. When a ferrule type spacer was simulated and implemented in both the center and side sub-channel, the vertical velocity of droplets got faster especially in the range of small diameter compared to the case of no spacer. When a grid type spacer was simulated and implemented in the center sub-channel especially, a large dispersion of vertical velocity of droplets occurred especially in the range of small diameter compared to the case of no spacer. By a computational fluid dynamics analysis for gas phase flow to drive the droplets in the sub-channel, it was confirmed qualitatively that the characteristics of droplet behavior observed in this experiment were dependent on the structure and geometry of spacer and sub-channel. Furthermore, it was revealed that a relation between a droplet diameter and velocity can be organized with a non-dimensional function derived from a momentum equation of particle in driving fluid and its drag coefficient has linear correlation with a gas Froude number.

    DOI

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Misc 【 display / non-display

  • Estimation of the In-Depth Debris Status of Fukushima Unit-2 and Unit-3 with Multi-Physics Modeling (6) Overview and Preliminary Criticality Evaluation of the Unit-3 Pedestal Debris

    山路哲史, 岸本和真, LI Xin, 古谷正裕, 佐藤一憲, 間所寛, 大石佑治

    日本原子力学会春の年会予稿集(CD-ROM)   2021  2021

    J-GLOBAL

  • Transient boiling analysis in partially and rapidly heated 5×5 rod bundle with TRACE code

    大川理一郎, 古谷正裕, 新井崇洋, 飯山継正, 白川健悦

    日本原子力学会春の年会予稿集(CD-ROM)   2021  2021

    J-GLOBAL

  • Development of void fraction in 5x5 rod bundle during saturated pool boiling on periodic heating conditions

    植田翔多, 新井崇洋, 宇井淳, 古谷正裕, 大川理一郎, 白川健悦

    日本原子力学会春の年会予稿集(CD-ROM)   2021  2021

    J-GLOBAL

  • Development of measurement method for concentration distribution of high electric conductivity solution

    飯山継正, 古谷正裕, 新井崇洋

    日本原子力学会春の年会予稿集(CD-ROM)   2021  2021

    J-GLOBAL

  • Research and development for understanding two-phase flow behavior inside a fuel bundle (9) Void fraction distribution in a rod bundle with cosine axial power profile

    新井崇洋, 宇井淳, 古谷正裕, 大川理一郎, 白川健悦

    日本原子力学会春の年会予稿集(CD-ROM)   2021  2021

    J-GLOBAL

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Industrial Property Rights 【 display / non-display

  • ガス中粒子の捕集方法、並びに、ガス中粒子捕集ノズル,スクラバ,及びベント装置

    特許第6760695号

    金井 大造, 古谷 正裕

    Patent

    J-GLOBAL

  • 温度センサ及び温度測定方法

    特許第6624610号

    滝口 広樹, 古谷 正裕

    Patent

    J-GLOBAL

  • 事故対策方法、原子力プラント及び放射線遮蔽方法

    神田 憲一, 阿部 数馬, 中村 康一, 宇井 淳, 西村 聡, 古谷 正裕, 西 義久

    Patent

    J-GLOBAL

  • 事故対策方法、原子力プラント及び放射線遮蔽方法

    神田 憲一, 阿部 数馬, 中村 康一, 宇井 淳, 西村 聡, 古谷 正裕, 西 義久

    Patent

    J-GLOBAL

  • 格子状計測装置

    滝口 広樹, 古谷 正裕

    Patent

    J-GLOBAL

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Research Projects 【 display / non-display

  • 伝熱面微細構の三次元多孔質造形と表面改質技術による冷却限界の飛躍的向上

    基盤研究(C)

    Project Year :

    2021.04
    -
    2024.03
     

    古谷 正裕

  • Construction of multiple micro interfaces using 3D microfluidic devices and application to functional chemical reactions

    Grant-in-Aid for Scientific Research (A)

    Project Year :

    2020.04
    -
    2023.03
     

  • Fundamental Study on Development of Corrosion Control Technique for Anti-corrosion Materials in Marine and Offshore Structures using Radiation Induced Surface Activation

    Grant-in-Aid for Scientific Research (B)

    Project Year :

    2007
    -
    2008
     

    TAKAMASA Tomoji, HAZUKU Tatsuya, ISHIMARU Takashi, MOYODA Shin-ichi, FURUYA Masahiro

  • Fundamental Study on Corrosion Control using Radiation Induced Surface Activation for Marine Use

    Grant-in-Aid for Scientific Research (B)

    Project Year :

    2005
    -
    2006
     

    TAKAMASA Tomoji, ISHIMARU Takashi, MOTODA Shinichi, HAZUKU Tatsuya, FURUYA Masahiro

     View Summary

    A corrosion mitigation technique based on radiation induced surface activation (RISA) from the gamma ray irradiation on a metal surface is reported in this paper. This study aimed to develop a RISA method to prevent crevice corrosion in SUS304 stainless steel using low-intensity radioactive material. Experiment showed that an electrode potential of -100 mV vs. Ag/AgCl was produced and maintained on TiO_2-coated SUS304 stainless steel specimens immersed in artificial seawater and in close contact with a small, sealed ^<60>Co source or activated by spontaneous neutron irradiation, with no corrosion observed for more than 7 days. On the contrary, the potential of the specimen without a radiation source decreased less than -280 mV vs. Ag/AgCl and crevice corrosion occurred beneath the O-ring within few days. The RISA effect of low-intensity radioactive material has the potential to prevent crevice corrosion of SUS304 stainless steel in actual seawater.

  • Corrosion Control for Internal Structure of Nuclear Reactor Based on Radiation Induced Surface Activation Phenomenon

    Grant-in-Aid for Scientific Research (B)

    Project Year :

    2003
    -
    2004
     

    TOMOJI Takamasa, MOTODA Shinichi, HAZUKU Tatsuya, UEMATSU Susumu, OKAMOTO Koji, FURUYA Masahiro

     View Summary

    When a semiconductor film is irradiated by γ-ray, excited electrons are transferred to a base metal in contact with the film, resulting in a drop of corrosion potential. This study proposes a corrosion mitigation method based on radiation induced surface activation(RISA) phenomena by supplying γ-rays from outside the material, or based on a self-excited methodology activating the film and/or the base metal. The results of the study revealed that electrons in the oxide film were activated by γ-ray irradiation and transferred from the oxide to the adjacent base metal. This made the corrosion potential of the metal less noble through a process in which the radiation induced a surface activation phenomenon, even in Zirconium oxide (ZrO_2) films which had large band gap energies. The mitigating method for the corrosion of metals was developed by utilizing this effect. The method involved external γ-rays irradiation introduced by activation of oxide films and/or base metals corrosion potential of ZrO_2 coated SUS304L was shifted down to the range between 90 mV and 300 mV vs. SSE by γ-ray irradiation. The corrosion potential was further shifted down to 600 mV when a CoCr intermediate layer was inserted between the ZrO_2 spray coating film and the SUS304L base metal. Iron specimens with a spray coating film of TiO_2,ZrO_2, and Al_2O_3 were immersed in a 3 wt% sodium chloride aqueous solution. Pitting and general corrosion were suppressed on all three specimens irradiated with γ-rays.
    These results clearly show that the corrosion potential of stainless steel could be less noble up to a level of -600 mV vs. SSE with this methodology and these processes would have a remarkable effect in mitigating the corrosion of stainless steels used in internal structures of nuclear reactors.

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Syllabus 【 display / non-display

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