火灾科学国家重点实验室陶尚青老师于2024年7月21日-7月27日参加第40届国际燃烧大会（40th International Symposium - Emphasizing Energy Transition），将在校内作相关分享报告。
报告时间：2024年8月2日 16:00
报告地点：火灾特种楼209会议室
报告题目：Buoyancy effect on extinction limits in low strain rate counterflow diffusion flames of methane
报告人简介：陶尚青，博士，中国科学技术大学特任副研究员。2022年6月获得中国科学技术大学安全科学与工程工学博士学位（导师：杨立中研究员，方俊副研究员），获安徽省优秀毕业生荣誉，2022年7月至今于中国科学技术大学开展研究工作。主要研究方向为微重力低拉伸率扩散火焰稳态燃烧，燃烧不稳定以及熄灭极限。以第一作者在国际燃烧学会两大会刊Combustion and Flame和Proceedings of the Combustion Institute等期刊上发表SCI论文7篇，主持国家自然科学基金青年项目1项，安徽省自然科学基金青年项目1项。研究工作得到了国家基金委、科技部、中科院以及安徽省的支持。
摘要：The buoyancy effect on the extinction limits of diluted methane/air counterflow diffusion flames are investigated experimentally at low strain rates, where the radiation heat loss and buoyancy effect play significant roles in flame extinction. Three curtain flow conditions (without, with He and N2 curtains) are tested to analyze the buoyancy effect by burnt gas. Considering a strategy of counterflow diffusion flame extinction by fuel dilution, He, N2, and CO2 are used as fuel diluents. The result shows that the He curtain flow could effectively minimize the buoyancy effect at low strain rate under the normal gravity, such that it could simulate the microgravity condition. The measured maximum temperature Tf of this simulated microgravity flames with He curtain decreases with decreasing strain rate, and the rank of Tf for various fuel dilutions is N2 > He > CO2. Three flow controlling regimes are identified as momentum-controlled, transition, and buoyancy-controlled regimes depending on the strain rate, based on the flame structure, temperature profile, and calculated Richardson number for the three curtain flow conditions. The magnitude of the buoyancy at very low strain rates under the normal gravity is characterized considering a buoyancy-induced strain rate ab, such that the 1-g experimental data can be corrected to a corresponding microgravity data. These could provide a guideline to 1-g experiment in simulating microgravity experiment. The very low strain flame extinction mechanism is further analyzed, considering the radiation loss fraction, which increases to a considerable level at very low strain rate, and CO2 dilution enhances the radiation effect on flame extinction.
