Study on laminar burning velocity determined from ignition

Reference No.	2024a031
Type/Category	Grant for General Research-Short-term Joint Research
Title of Research Project	Study on laminar burning velocity determined from ignition
Principal Investigator	Youhi Morii（Institute of Fluid Science, Tohoku University・Assistant Professor）
Research Period	June 17,2024. - June 21,2024. January 14,2025. - January 15,2025.
Keyword(s) of Research Fields	Laminar burning velocity, Premixed flame, Ignition
Abstract for Research Report	Combustion is widely used as an energy source utilizing thermal energy. Furthermore, the application of hydrogen, ammonia, and synthetic fuels produced from carbon dioxide as alternatives to fossil fuels is being considered, where conventional knowledge about combustion may not apply. Therefore, improving the efficiency of combustors is crucial as it can directly reduce carbon dioxide emissions. However, combustion is a field that has been utilized for a long time, and numerous research and development efforts have been made. In other words, to achieve further efficiency improvements, it is necessary to utilize combustion conditions that have traditionally been avoided due to their strong instability. Additionally, the application of hydrogen, ammonia, and synthetic fuels is being considered. In this research, by revisiting the fundamentals of combustion, the applicant aims to establish a universal understanding that is independent of fuels and combustion conditions, and provide a theory that contributes to the efficiency improvement of practical combustor development. Currently, the theory constructed by the applicant is being applied to fuels with high Lewis numbers, and for instance, the conditions for the occurrence of knocking, which has been the major issue in SI engines, have been clarified for n-heptane (one of the main components of gasoline fuel) with a high Lewis number. However, fuels such as hydrogen and ammonia have low Lewis numbers, and further research is expected. Additionally, a phenomenon called autoignition assisted flame, where the flame speed is promoted by autoignition in front of the reaction zone, has been confirmed under combustion conditions that have traditionally been avoided. Therefore, by finding a method to derive flame speeds with a wide range of applicability, it becomes possible to expand the combustion conditions and directly contribute to efficiency improvements.
Organizing Committee Members (Workshop) Participants (Short-term Joint Usage)	Youhi Morii（Institute of Fluid Science・Assistant Professor）