Effects of Fuel Composition on Initial Flame Kernel Growth and Minimum Ignition Energy

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04327
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Osaka University
• Principal Investigator: Hori Tsukasa 大阪大学, 大学院工学研究科, 講師 (40744066)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 火花点火 / プラズマ / 数値解析 / 層流燃焼速度 / 内燃機関 / 火花点火機関 / 火炎核

Outline of Final Research Achievements

The objective of this study was to investigate the effects of fuel composition on initial flame growth and minimum ignition energy. First, a sphere-propagating flame measurement system was constructed using a fixed volume vessel. The fuels used were methane, ammonia, hydrogen, heptane, and their mixtures. The growth rate of the flame kernel and laminar flame speed were measured, and data were obtained to verify the reaction mechanism in the case of co-combustion. Next, we developed a method to calculate the flame kernel growth from spark discharges considering thermal plasmas, and succeeded in predicting the extension, re-discharge, and short-circuit phenomena of spark channel under flow. Furthermore, we succeeded in predicting the fuel composition on the minimum ignition energy by using the reaction mechanism.

Free Research Field

燃焼工学

Academic Significance and Societal Importance of the Research Achievements

本研究では，メタンに加えて，カーボンフリー燃料である水素やアンモニアを組み合わせた場合の燃焼特性を実験により計測するとともに，プラズマを含む多成分系での燃焼の数値解析手法を開発した．本成果により，反応計算の精度改善が期待できるとともに，これまで実現が難しかった最小点火エネルギを計算により予測できるようになった．本研究の成果により，内燃機関の効率改善に最適な燃料の組み合わせの机上検討が実施できるようになり，内燃機関における水素，アンモニア，合成燃料の燃焼利用促進が期待される．