Elucidation and Control of Wall Effects on Cool Flame

2020 Fiscal Year Final Research Report

• Project/Area Number: 18KK0106
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Suzuki Yuji 東京大学, 大学院工学系研究科(工学部), 教授 (80222066)
• Co-Investigator(Kenkyū-buntansha): 范 勇 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (40748662) ; 齋木 悠 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (60550499) ; 李 敏赫 東京大学, 大学院工学系研究科(工学部), 助教 (80828426)
• Project Period (FY): 2018-10-09 – 2021-03-31
• Keywords: 燃焼 / 壁面効果 / 表面反応 / 冷炎 / 熱炎 / レーザー誘起蛍光法

Outline of Final Research Achievements

In this study, in collaboration with Professor Ju of Princeton University, who is a world authority on low-temperature oxidation reaction, evaluation of the wall chemical effect in the ignition process of cold flame, evaluation of radical adsorption reaction by radical beam scattering, the radical surface recombination reaction in wall-attached flame were investigated. As a result, the influence of the wall chemical effect is more significant in the cold flame than in the hot flame, and the ignition / extinction temperature may rise or fall depending on the wall chemical effect for each material. The wall chemical effects in hot flame can be explained by the radical decay model by considering the wall sticking coefficient that differs for each radical. On the other hand, for the cool flame, for the first time, it was clarified that desorption of the surface of radicals and adsorption / decomposition of stable chemical species should play a dominant role.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

冷炎は，例えばHCCIエンジンの着火過程を考える上で極めて重要であり，本研究を通じて得られた，低温酸化反応，冷炎の着火と消炎，冷炎に対する壁面の化学的効果について得られた知識は，新規性が高く，燃焼工学分野に新しい展開を加えることができたと考えている．
また，本研究を通じて構築した，高変換効率の２光子吸収レーザー誘起蛍光法，分子線散乱によるラジカル吸着反応の計測手法などの研究手法についても，今後関連分野での展開が期待できる．