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BASIC STUDIES ON THE DEVELOPMENT OF HIGHLY EFFICIENT COMPACT HEAT EXCHANGER WITH LOW ENVIRONMENTAL LOAD

Research Project

Project/Area Number14550181
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Thermal engineering
Research InstitutionKYOTO INSTITUTE OF TECHNOLOGY

Principal Investigator

HAGIWARA Yoshimichi  KYOTO INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING AND DESIGN, PROFESSOR, 工芸学部, 教授 (50144332)

Co-Investigator(Kenkyū-buntansha) TANAKA Mitsuru  KYOTO INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING AND DESIGN, ASSOCIATE PROFESSOR, 工芸学部, 助教授 (20281115)
Project Period (FY) 2002 – 2003
Project Status Completed(Fiscal Year 2003)
Budget Amount *help
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 2003 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 2002 : ¥2,700,000 (Direct Cost : ¥2,700,000)
Keywordsliquid-liquid direct contact / high-density inactive liquid / upward water flow / PLIF / PTV / direct numerical simulation / near-wall turbulence structure / local heat transfer / 局所熱伝導 / 液液直接接触熱交換 / 上昇水乱流 / 粒子画像速度計測法 / 乱流熱流束
Research Abstract

The experiments were conducted for the upward water flow in a vertical pipe with falling immiscible droplets of hydrofluoroether (HFE-7200) or perfluorocarbon (FC-72). The visualization of velocity field and temperature field and image processing were carried out.
(1) The HFE-7200 droplets fall with noticeable wobbling in the near-wall region of the turbulent upward water flow. On the other hand, the droplets whose specific weight is higher than that of hFE-7200 fall with small-amplitude wobbling in the central region. The increases in the turbulence intensities and the decrease in the mean velocity are measured in the region of droplet passing. The vortices in the wake flow of the droplets cause the change in the turbulence statistics. The outward or wallward flow induced by the flow of HFE-7200 droplets affects the near-wall coherent structure.
(2) The Strouhal number for the droplet motion can be estimated from the empirical of rising bubbles. This Strouhal number is lower than the St … More rouhal number of vortex shedding from a solid sphere.
(3) The circular fluid motion was observed in the wake flow region. This motion is considered to be the cross sections of the unsteady Ω-shaped vortex tube. The thermal wake region is smaller than the area of passing the Ω-shaped vortex tube in the wake flow. This is because the Prandtl number is high and because high-temperature fluid outside the tube was carried into the wake flow region surrounded by vortex tube.
(4) The high velocity flow in the wall jet between the funnel and the pipe inner wall decelerated the droplet falling velocity. The droplet was easily transported in the central region by the wall-normal fluctuating velocity generated by the tripping wire. The funnel and tripping wire allocated near the bottom of the test section worked well for collecting all the descent droplets.
The direct numerical simulation was carried out for turbulent upward flow between two heating walls with four immiscible droplets. The main conclusions obtained are as follows.
(1) The droplet induced several types of secondary flows. These flows increased the Reynolds shear stress product. These flows were attenuated by the adjacent in the streamwise direction. The small-scale streamwise vortices were attenuated near the droplets. The large-scale developed streamwise vortices were deformed by the droplets.
(2) The product of wall-normal velocity fluctuation and the temperature fluctuation increased by the secondary flows. This shows an enhancement of turbulent heat transfer by droplets. Less

Report

(3results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report

Research Products

(21results)

All Other

All Publications

  • [Publications] Y.Hagiwara, T.Yuge, S.Takagaki: "Heat Transfer Enhancement by an Immiscible Droplet Wobbling in Near-wall Region of Turbulent Downward Liquid Flow"J.of Enhanced Heat Transfer. Vol.10. 81-93 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Yuge, Y.Hagiwara: "The Modifications of Near-wall Turbulence Structure and Heat Transfer by Immiscible Droplets in Turbulent Liquid-liquid Two-phase Flow"Int.J.Heat and Fluid Flow. Vol.25(in print). (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Y.Hagiwara, T.Suzaki, D.Saegusa: "Interaction between Near-wall Turbulence Structure and Immiscible Droplets Falling with Wobbling Motion in Upward Water Flow"Int.J.of Energy. Vol.29(to appear). (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] M.Goto, N.Matsukura, Y.Hagiwara: "Heat Transfer Characteristics of Warm Water Flow with Cool Immiscible Droplets in a Vertical Pipe"Experimental Thermal and Fluid Science. Vol.28(to appear). (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Tajima, N.Matsukura, M.Tanaka, Y.Hagiwara: "Control of Droplet Motion by Wall Jet and a Turbulence Promoter in Turbulent Dispersed Liquid-liquid Two-phase Flow in a Pipe"Turbulence, Heat and Mass Transfer 4 (ed.by K.Hanjalic, Y.Nagano, M.J.Tummers), Begell House Inc.. 1031-1038 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Hagiwara Y., Takagaki S., Yuge T.: "Effects of a droplet on near-wall transport phenomena in turbulent downward liquid-liquid flow"J. Enhanced Heat Transfer. Vol.10. 81-93 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Yuge T., Hagiwara Y.: "The modifications of near-wall turbulence structure and heat transfer by immiscible droplets in turbulent liquid-liquid two-phase flow"Int. J. Heat and Fluid Flow. Vol.25 (in press). (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Hagiwara Y., Suzaki T., Saegusa D.: "Interaction between near-wall turbulence structure and immiscible droplets falling with wobbling motion in upward water flow"Int. J. of Energy. Vol.29 (to appear). (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Goto M., Matsukura N., Hagiwara Y.: "Heat transfer characteristics of warm water flow with cool immiscible droplets in a vertical duct"Experimental Thermal and Fluid Science. Vol.28 (to appear). (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Tajima M., Matsukura N., Tanaka M., Hagiwara Y.: "Control of droplet motion by wall jet and turbulence promoter in turbulent dispersed liquid-liquid two-phase flow in a pipe"Turbulence, Heat and Mass Transfer 4 (ed. by K.Hanjalic, Y. Nagano, M. J. Tummers) (Begell House, Inc.). 1031-1038 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Yuge, Y.Hagiwara: "The Modifications of Near-wall Turbulence Structure and Heat Transfer by immiscible Droplets in Turbulent Liquid-liquid Two-phase Flow"Proc.3rd Int.Symposium of Turbulence and Shear Flow Phenomena. Vol.1. 221-226 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] T.Tajima, N.Matsukura, M.Tanaka, Y.Hagiwara: "Control of Droplet Motion by Wall Jet and a Turbulence Promoter in Turbulent Dispersed Liquid-liquid Two-phase Flow in a Pipe"Turbulence, Heat and Mass Transfer 4 (ed.by K.Hanjalic, Y.Nagano, M.J.Tummers), Begell House Inc.. 1031-1038 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Goto, N.Matsukura, Y.Hagiwara: "Heat Transfer Characteristics of Warm Water Flow with Cool Immiscible Droplets in a Vertical Pipe"Proc.3rd European-Japanese Two-phase Flow Group Meeting. (CD-ROM). 1-7 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] T.Yuge, Y.Hagiwara: "The Modifications of Near-wall Turbulence Structure and Heat Transfer by Immiscible Droplets in Turbulent Liquid-liquid Two-phase Flow"Int.J.Heat and Fluid Flow. Vol.25(in print). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Hagiwara, T.Suzaki, D.Saegusa: "Interaction between Near-wall Turbulence Structure and Immiscible Droplets Falling with Wobbling Motion in Upward Water Flow"Int.J.of Energy. Vol.29(to appear). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Goto, N.Matsukura, Y.Hagiwara: "Heat Transfer Characteristics of Warm Water Flow with Cool Immiscible Droplets in a Vertical Pipe"Experimental Thermal and Fluid Science. Vol.28(to appear). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] 弓削拓治, 萩原良道, 田中満: "高密度不溶性液滴を含むチャネル乱流の熱伝達に関する直接数値シミュレーション"第16回数値流体力学シンポジウム講演論文集. E11.4.1-E11.4.5 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Hagiwara, T.Yuge, S.Takagaki: "Heat Transfer Enhancement by an Immiscible Droplet Wobbling in Near-wall Region of Turbulent Downward Liquid Flow"J.of Enhanced Heat Transfer. Vol.10. (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Tajima, Y.Hagiwara, N.Matsukura: "Turbulent upward pipe flow with immiscible droplets"Proc.UK-Japan Seminar on Multiphase Flow 2003. (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] N.Matsukura, M.Goto, M.Tajima, Y.Hagiwara: "Velocity and temperature measurement for natural convection flow with an immiscible droplet in a small water tank"Proc.UK-Japan Seminar on Multiphase Flow 2003. (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] 田島正博, 松倉紀行, 後藤雅志, 萩原良道: "沈降する不溶性液滴を含む鉛管内上昇水乱流の計測"第40回日本伝熱シンポジウム講演論文集. (2003)

    • Related Report
      2002 Annual Research Report

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Published : 2002-04-01   Modified : 2016-04-21  

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