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Micro-droplets levitated over hot water: Physics of coffee steam

Research Project

Project/Area Number 25610124
Research Category

Grant-in-Aid for Challenging Exploratory Research

Allocation TypeMulti-year Fund
Research Field Biological physics/Chemical physics/Soft matter physics
Research InstitutionKyushu University

Principal Investigator

Nakanishi Hiizu  九州大学, 理学研究院, 教授 (90155771)

Co-Investigator(Kenkyū-buntansha) 市川 正敏  京都大学, 理学研究科, 講師 (40403919)
Co-Investigator(Renkei-kenkyūsha) SAKAUE Takahiro  九州大学, 理学研究院, 助教 (30512959)
Project Period (FY) 2013-04-01 – 2017-03-31
Project Status Completed (Fiscal Year 2016)
Budget Amount *help
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Keywords微小水滴 / 凝集 / 茶碗の湯 / 表面張力波 / 水蒸気 / 界面
Outline of Final Research Achievements

When drinking a cup of coffee under the morning sunshine, you may notice white membranes of steam floating on the surface of the hot water. They stay notably close to the surface and appear to almost stick to it. Although the membranes whiffle because of the air flow of rising steam, peculiarly fast splitting events occasionally occur. They resemble cracking to open slits approximately 1mm wide in the membranes, and leave curious patterns. We studied this phenomenon using a microscope with a high-speed video camera and found intriguing details: i) the white membranes consist of fairly monodispersed small droplets of the order of 10μm; ii) they levitate above the water surface by 10-100μm; iii) the splitting events are a collective disappearance of the droplets, which propagates as a wave front of the surface wave with a speed of 1-2 m/s; and iv) these events are triggered by a surface disturbance, which results from the disappearance of a single droplet.

Report

(5 results)
  • 2016 Annual Research Report   Final Research Report ( PDF )
  • 2015 Research-status Report
  • 2014 Research-status Report
  • 2013 Research-status Report
  • Research Products

    (8 results)

All 2016 2015 2014 2013

All Journal Article (2 results) (of which Peer Reviewed: 2 results,  Open Access: 1 results,  Acknowledgement Compliant: 1 results) Presentation (6 results) (of which Int'l Joint Research: 1 results,  Invited: 1 results)

  • [Journal Article] コーヒーの湯気:水面に浮遊する微小水滴のダイナミクス2016

    • Author(s)
      中西秀、市川正敏
    • Journal Title

      日本物理学会誌

      Volume: 71

    • NAID

      130005420421

    • Related Report
      2016 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Dynamics of microdroplets over the surface of hot water2015

    • Author(s)
      Takahiro Umeki, Masahiko Ohata, Hiizu Nakanishi, and Masatoshi Ichikaw
    • Journal Title

      Scientific Reports

      Volume: 5 Issue: 1 Pages: 8046-8046

    • DOI

      10.1038/srep08046

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Presentation] Dynamics of microdropltes over the surface of hot water2016

    • Author(s)
      Hiizu Nakanishi
    • Organizer
      EMN meeting on Droplets 2016
    • Place of Presentation
      San Sebastian, Spain
    • Year and Date
      2016-05-09
    • Related Report
      2016 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 熱水面上に浮遊する微小水滴のサイズ分布と温度の相関2015

    • Author(s)
      梅木崇浩,中西秀,市川正敏
    • Organizer
      日本物理学会
    • Place of Presentation
      早稲田大学
    • Year and Date
      2015-03-24
    • Related Report
      2014 Research-status Report
  • [Presentation] コーヒーカップの中の嵐:熱水上に浮かぶ微小水滴とそのダイナミクス2015

    • Author(s)
      中西 秀、梅木 崇浩、市川 正敏
    • Organizer
      第4回ソフトマター研究会
    • Place of Presentation
      名古屋大学
    • Year and Date
      2015-01-06 – 2015-01-08
    • Related Report
      2014 Research-status Report
  • [Presentation] 熱水上に浮遊する微小水滴とその集団消滅現象2014

    • Author(s)
      梅木崇浩,中西秀,市川正敏
    • Organizer
      日本物理学会
    • Place of Presentation
      中部大学
    • Year and Date
      2014-09-08
    • Related Report
      2014 Research-status Report
  • [Presentation] コーヒーの湯気~浮遊する微小水 滴とその集団消滅~2014

    • Author(s)
      市川正敏
    • Organizer
      日本物理学会
    • Place of Presentation
      東海大学
    • Related Report
      2013 Research-status Report
  • [Presentation] Storm in a Teacup: dynamics of micro-droplets on hot water surface2013

    • Author(s)
      Hiizu Nakanishi
    • Organizer
      International Soft Matter Conference 2013
    • Place of Presentation
      ローマ、イタリア
    • Related Report
      2013 Research-status Report

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Published: 2014-07-25   Modified: 2019-07-29  

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