| Project/Area Number |
21K03899
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 19020:Thermal engineering-related
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| Research Institution | Kyushu University |
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Principal Investigator |
Moriue Osamu 九州大学, 工学研究院, 教授 (70363124)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Project Status |
Completed (Fiscal Year 2023)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2023: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2021: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 燃焼 / 噴霧 / 自着火 |
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| Outline of Research at the Start |
燃料噴霧の自着火のモデル化の礎とすべく，粒形分布を持つ燃料液滴群の自着火を支配する因子（液滴径，液滴径分散，液滴間隔，温度，圧力，燃料性状）を抽出する．実用噴霧サイズの直径数10ミクロン程度の微小液滴の自着火特性を実験的に調査し，微小液滴の蒸発速度，冷炎・熱炎の着火遅れの雰囲気依存性を明らかにする．また，直径1mm程度の異なる大きさの粗大二液滴の自着火実験を行い，液滴間干渉に液滴径の分散が及ぼす影響を調査する．両実験を通して研鑽された数値計算を用い，目的を達成する．
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| Outline of Final Research Achievements |
A fundamental study on spontaneous ignition of fuel spray in hot ambient gas was carried out. Ignition behavior of an isolated fine fuel droplet whose diameter is about dozens of microns was experimentally and numerically studied. Evaporation rates obtained by the experiments were almost comparable with those of numerical analysis, while ignition delays of cool flame were not comparable. Ignition behavior of a fuel droplet pair was also experimentally and numerically studied. In most conditions cool flame appears from the outside of the pair. However, in several conditions cool flame appears between the droplets. The behavior above was explained by numerical analysis considering Damkoehler number as one of controlling factors.
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| Academic Significance and Societal Importance of the Research Achievements |
単一微小液滴について，冷炎の自着火遅れに実験と数値解析で隔たりが見られたが，特に逆火や過早着火を予測する数値解析においては，冷炎発生限界近傍における化学反応モデルの信頼性の改良が要されることが示唆される．冷炎を発生する低温酸化反応は温度依存性が高く，粗大二液滴の実験においては，従来二液滴の外側の高温部でのみ冷炎が発生することが確認されていたが，数値計算上初期液滴径を減少させると液滴間で冷炎が発生し得ることが確認された．反応場の局所的な温度，濃度の履歴が自着火の有無，場所を支配する因子として扱われてきたが，局所ダムケラ―数も支配因子として重要であることを示している．
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