Elementary Process of Spontaneous Ignition of Fuel Spray

• Project/Area Number: 18K03986
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Kyushu University
• Principal Investigator: Moriue Osamu 九州大学, 工学研究院, 教授 (70363124)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 燃焼 / 噴霧 / 自着火

Outline of Final Research Achievements

As an elementary process of spontaneous ignition of fuel spray, fuel droplet clouds were studied. It was experimentally shown that evaporation rate of fine droplets with the diameters of about dozens of microns is comparable to that of large droplets, and that detection of cool-flame appearance around such fine droplets is possible through the observation of droplet-diameter history. Droplet interaction was studied through the experiments of spontaneous ignition of a large-droplet pair whose diameters are different. The effect of droplet interaction on spontaneous ignition depends complicatedly on the conditions such as droplet diameter, inter-droplet distance and ambient gas condition, which was explained with the help of numerical calculation.

Academic Significance and Societal Importance of the Research Achievements

噴霧燃焼の基礎研究として単一もしくは複数の燃料液滴を扱う研究はこれまで多く行われてきたが，実験時の空間的・時間的分解能の確保のために直径1mm程度の粗大液滴が対象とされた．本研究では実用噴霧と同サイズの数10ミクロンの液滴の蒸発特性が実験的に観測され，従来の理論の適用が可能であることが確認された．また，複数液滴における液滴間干渉については同一径であることがこれまで前提であったが，液滴径の違いの影響が調査され，概して小さい液滴の存在が系全体の現象に対して支配的であるが，着火限界近傍では異なることが確認された．噴霧燃焼のモデル化において，粒度分布の評価が重要であることを示唆する．

Research Products

• [Journal Article] Scope of PHOENIX-2 Sounding Rocket Experiment, “Cool Flame Dynamics in Multi-droplet Ignition” (2020)
  • Author(s): Mitsuaki TANABE, Masanori SAITO, Yusuke SUGANUMA, Masato MIKAMI, Masao KIKUCHI, Yuko INATOMI, Osamu MORIUE, Hiroshi NOMURA
  • Journal Title: International journal of microgravity science and application Volume: 37 Issue: 4 Pages: 370401
  • DOI: 10.15011/jasma.37.4.370401
  • NAID: 130007934388
  • ISSN: 2188-9783
  • Year and Date: 2020-10-31
  • Peer Reviewed / Open Access
• [Journal Article] Hardware Development for Cool Flame Combustion Experiment of Fuel Droplets using Sounding Rocket (2020)
  • Author(s): 菅沼 祐介, 齊藤 允教, 後藤 芳正, 山村 宜之, 山本 信, 野倉 正樹, 三上 真人, 菊池 政雄, 稲富 裕光, 森上 修, 野村 浩司, 田辺 光昭
  • Journal Title: International journal of microgravity science and application Volume: 37 Issue: 4 Pages: 370403
  • DOI: 10.15011/jasma.37.4.370403
  • NAID: 130007934427
  • ISSN: 2188-9783
  • Year and Date: 2020-10-31
  • Peer Reviewed / Open Access
• [Presentation] 初期液滴径の異なる二液滴系における冷炎発生挙動に関する数値計算 (2020)
  • Author(s): 田中 大也，安藤 詩音，森上 修
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] ガウス過程による補間モーメントを用いた炭化水素燃料の0次元すす生成計算 (2020)
  • Author(s): 安藤 詩音，森上 修
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] Numerical study on evaporation and low-temperature oxidization of a droplet pair with different diameters (2019)
  • Author(s): Satoshi TAKAHASHI, Hiroya TANAKA , Hiromu NAKAMURA, Osamu MORIUE
  • Organizer: 20th Annual Conference on Liquid Atomization and Spray Systems - Asia
  • Int'l Joint Research
• [Presentation] 直径の異なる二液滴の蒸発および冷炎発生の数値計算 (2019)
  • Author(s): 高橋聡史，森上修，田中大也，中村大夢
  • Organizer: 日本マイクログラビティ応用学会 第31回学術講演会
• [Presentation] 直径の異なる二液滴の自発点火における液滴間干渉 (2019)
  • Author(s): 中村大夢，木原一穣，田中森悟，森上修
  • Organizer: 第57回燃焼シンポジウム
• [Presentation] 直径の異なる二液滴の蒸発の数値計算 (2018)
  • Author(s): 高橋 聡史，森上 修
  • Organizer: 第56回燃焼シンポジウム
• [Presentation] 直径の異なる二液滴の自発点火に液滴間干渉が及ぼす影響 (2018)
  • Author(s): 中村 大夢，高橋 聡史，森上 修
  • Organizer: 第56回燃焼シンポジウム