气体火焰的碳烟生成是微重力科学研究中的热点问题。在微重力下开展气体火焰的碳烟生成研究, 不仅有利于了解空间站等微重力设施中的火灾行为, 也能够规避自然对流影响获得更加理想的火焰, 从而深入理解碳烟的生成过程, 为理论研究提供数据支撑。该文系统描述了微重力下气体火焰碳烟生成规律的研究进展, 重点介绍了微重力气体火焰的碳烟生成路径和烟点研究, 总结了影响微重力下碳烟形成的主要因素。经分析得出, 在微重力下气体扩散火焰的碳烟生成与在常重力下显著不同, 已有研究通过光学诊断等方法揭示了微重力下碳烟生成的基本特征和火焰形态变化规律。结合微重力实验, 已有研究总结出了微重力下气体扩散火焰烟点的预测模型, 并发现烟点与燃料种类、射流直径和伴流速度密切相关。气流流速、氧气浓度、稀释剂、压力、预热和电磁场对碳烟浓度都有较为重要的影响。然而, 当前研究依然以定性描述居多, 与常重力实验相比, 微重力实验已利用的先进诊断技术依然有限, 仍需要开展多因素耦合研究, 结合先进的诊断技术, 进一步深入研究不同燃料多因素耦合对碳烟生成的综合影响, 从而揭示碳烟生成的本质规律, 发展更为完善的碳烟生成和氧化的预测模型。此外, 中国空间站的燃烧实验柜已经配备现有国际上非常先进的微重力燃烧研究诊断技术, 可为该领域的发展提供重要支撑。

Significance: Research on soot formation in gas flames under microgravity conditions is a key area in combustion science. Studying soot production in microgravity environments not only elucidates fire behavior in space stations but also eliminates the influence of natural convection, creating a more controlled flame environment for detailed exploration of soot formation processes. The importance of microgravity research lies in its ability to provide essential data for advancing theoretical models and clarifying soot formation mechanisms. This research holds valuable implications for improving combustion technologies, benefiting applications on Earth and in space. Progress: This paper presents a comprehensive review of recent advances in the study of soot formation in gas flames under microgravity conditions. The review systematically summarizes research progress, emphasizing soot formation pathways, smoke point studies, and primary factors influencing soot formation in microgravity. Key methods covered include both qualitative and quantitative analyses, with a focus on advanced diagnostic techniques such as flame emission spectroscopy and laser-induced incandescence, which provide detailed data on soot concentration, particle size, and distribution. The findings indicate that most current research is centered on qualitative descriptions of soot formation, with a marked gap in quantitative analysis and detailed mechanistic insights. The necessity of multifactor coupling studies under microgravity is also highlighted to clarify the combined effects of variables such as fuel type, oxygen concentration, pressure, flow rate, and preheating on soot formation. Advanced diagnostic techniques are increasingly becoming essential tools for measuring soot concentration in space experiments. Conclusions and Prospects: The review concludes that although substantial progress has been achieved, future research should prioritize more detailed quantitative analyses and the development of comprehensive models to uncover fundamental soot formation mechanisms. Continued advancements and application of diagnostic techniques in space experiments are essential. Potential research directions include exploring novel diagnostic methods, improving measurement accuracy and reliability, and examining the effects of various external conditions on soot formation. As space research facilities, such as the Chinese Space Station, continue to advance, these developments will support more comprehensive experimental designs, multifactor coupling studies, and the integration of advanced diagnostic techniques with numerical simulations. These efforts will be critical for devising effective soot control strategies, thereby advancing combustion science and promoting cleaner, more efficient combustion technologies for both space and terrestrial applications. The review calls for collaborative efforts within the scientific community to leverage the advancements in microgravity research to further elucidate soot formation processes.