Elucidation and modeling of wall chemical effect with plasma techniques and combustion diagnostics

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02075
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Saiki Yu 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (60550499)
• Co-Investigator(Kenkyū-buntansha): 杵淵 郁也 東京大学, 大学院工学系研究科(工学部), 准教授 (30456165)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 燃焼 / 壁面効果 / 表面反応 / ラジカル / プラズマ

Outline of Final Research Achievements

Prediction of flame-wall interaction is of great importance for development of downsized combustors. The solid wall imposes fluidic, thermal, and chemical boundaries affecting flame characteristics. In this study, wall chemical effect caused by radical adsorption and recombination on wall surfaces is investigated by using newly-developed two different types of plasma techniques as well as combustion diagnostics. Firstly, adsorption of H and O radicals, which play a key role in the wall chemical effect, are directly measured through molecular beam scattering technique using a non-equilibrium plasma-driven beam source with an ultra-high vacuum chamber. Non-equilibrium plasma jets are also employed to examine H and O adsorption at atmospheric-pressure. In addition, H radical recombination are evaluated using a wall stagnation flame. The near-wall H2 concentration is analyzed by gas-chromatography and compared with numerical results using detailed gas/surface chemistry.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

火炎に与える壁面の効果には，壁への熱損失に起因する熱的効果に加え，火炎内のラジカルが壁面に吸着し再結合して消失する化学的効果が存在する．しかし，化学的効果に関しては，ラジカル表面反応の評価が難しいことから，そのメカニズムは未解明のままにされてきた．本研究は，従来情報が少ないラジカルの表面反応過程をプラズマなどを活用した独自の技術により評価したものであり，種々の燃焼装置における壁面効果の解析手法の確立に大きく寄与すると言える．広く社会には，内燃機関の低環境負荷化，燃料改質器の高性能化，付加価値の高い超小型エネルギー源の創成などに関連して，持続型社会の構築とQOLの向上に貢献するものと考えられる．