PM formation processes inside autoignited fine fuel-droplet clusters

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04922
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Osaka Metropolitan University (2022-2023); Osaka Prefecture University (2020-2021)
• Principal Investigator: Segawa Daisuke 大阪公立大学, 大学院工学研究科, 教授 (00264804)
• Co-Investigator(Kenkyū-buntansha): 片岡 秀文 大阪公立大学, 大学院工学研究科, 講師 (10548241)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 液滴群燃焼 / 自発着火 / PM / 冷炎 / すす

Outline of Final Research Achievements

A temperature rise which was assumed to be due to cool flame was observed near droplet even at atmospheric pressure, when clusters of fine fuel droplets and single fuel droplets were introduced into high-temperature air ambience. Delay of the temperature rise decreased with increasing the ambient air temperature, while the delay turned to increase just below the air temperature for autoignition with hot flame appearance. Soot was formed inside and outside of the clusters and around the droplets just after the ignition, when the clusters and the droplets were introduced into high-temperature air to autoignite. Amount of the soot was observed to decrease gradually in the latter half of the burning time. The amount reached maximum when droplet spacing was around six-times of the initial droplet diameter.

Free Research Field

航空宇宙工学関連

Academic Significance and Societal Importance of the Research Achievements

自動車のPM，PN規制が強化されるなど，燃焼によるすす生成への対策が強く求められている．そのため，多様な状況下でのすす生成挙動の詳細が明らかにされ，すす生成の数値シミュレーション手法も大幅に発展したが，低い計算負荷で精度良く計算できるようなすす生成の簡略反応モデルが必要とされている．本研究の実験結果は，そのような簡略反応モデルの開発のための検証データになるものと期待される．