Predicted ignitability index based on the molecular structures of hydrocarbons for modern diesel combustion

• Project/Area Number: 17K06177
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Hokkaido University
• Principal Investigator: Ogawa Hideyuki 北海道大学, 工学研究院, 教授 (40185509)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: ディーゼルエンジン / 着火遅れ / セタン価 / アレニウス式 / 酸素濃度 / 温度 / 圧力 / 圧縮比 / アレニウスの式 / 着火性 / 燃料 / 排気再循環 / 過給圧力 / 吸気温度

Outline of Final Research Achievements

To understand the dependence of ignition delay on the cetane number under various super-charging and EGR conditions in diesel combustion, ignition delays were systematically measured in a 0.83L single cylinder diesel engine. The investigations were conducted over a wide range of intake oxygen concentrations, intake gas temperatures, intake pressures, and cetane numbers to develop an empirical formula for the ignition delay based on the Arrhenius equation. The final proposed equation can adequately predict ignition delays with three parameters: the cetane number as well as the in-cylinder gas temperature and the oxygen partial pressure at the start of the fuel injection. The equation can predict ignition delays shorter than 2.0 ms, but the calculated ignition delays are longer than the experimental data when the ignitio delays exceed 2.0 ms. This is due to the earlier fuel injection timings with the longer ignition delay to maintain the ignition timing at TDC.

Academic Significance and Societal Importance of the Research Achievements

ディーゼルエンジンにおける着火遅れは，機関性能および排気特性に対して大きな影響を与えるため，その把握はきわめて重要であるのに対して，広域かつ多様に変化するエンジン燃焼室内雰囲気条件と着火遅れとの関係を体系的に調査した例は少ない．広範な運転条件およびセタン価に対して適用可能な着火遅れ予測式を構築できれば，ディーゼルエンジンの高効率・高性能・低エミッション化に資する成果となることが期待できる．

Research Products

• [Journal Article] Ignition delays in diesel combustion and intake gas conditions (2018)
  • Author(s): Hideyuki Ogawa, Akihiro Morita, Katsushi Futagami, and Gen Shibata
  • Journal Title: International Journal of Engine Research (IMech E) Volume: 19 Pages: 805-812
  • Peer Reviewed
• [Journal Article] Predicted diesel ignitability index based on the molecular structures of hydrocarbons (2018)
  • Author(s): Hideyuki Ogawa, Hideyuki Nishimoto, Akihiro Morita, and Gen Shibata
  • Journal Title: International Journal of Engine Research Volume: -
  • NAID: 130007065971
  • Peer Reviewed / Open Access
• [Presentation] ディーゼルエンジンにおける着火遅れの運転条件に対する依存性 (2019)
  • Author(s): 山﨑泰助，菅野椋太，坂根悠平，小橋好充，柴田元，小川英之
  • Organizer: 第30回内燃機関シンポジウム
• [Presentation] EGRガスの組成がディーゼル燃焼の着火遅れに及ぼす影響 (2018)
  • Author(s): 外処将貴，大岡峻，小橋好充，柴田元，小川英之
  • Organizer: 自動車技術会2018年秋季大会 学術講演会
• [Presentation] Ignition Delays in Diesel Combustion and Intake Gas Conditions (2017)
  • Author(s): Hideyuki Ogawa, Akihiro Morita, Katsushi Futagami and Gen Shibata
  • Organizer: SAE 2017 International Powertrains, Fuels & Lubricants Meeting
  • Int'l Joint Research