碳氢燃料在超临界燃烧极端热力学条件下存在积炭和燃烧不稳定等科学技术难题，已成为发展先进空天发动机必须突破的关键科学问题之一。目前，关于碳氢燃料/氧超临界燃烧的基础研究较少，本课题以碳氢燃料/氧超临界燃烧特性为研究目标，展开极端热力学条件下层流扩散火焰结构和稳定性的研究，分析碳氢燃料/氧超临界燃烧层流扩散火焰边界特征、火焰结构和火焰形态转变规律，建立火焰结构特征参数与燃烧参数之间的函数关系，分析燃烧压力和流量对火焰震荡幅度、波长和频率的影响机制；通过检测火焰温度、碳烟浓度和自由基OH 浓度等分布，并结合详细燃烧反应机理分析，提出碳氢燃料/氧超临界燃烧层流扩散燃烧火焰反应功能分区精细结构，分析各分区燃烧化学反应机制；建立燃烧模型，探索复杂耦合扩散对碳烟生成和火焰结构的影响机制；深入揭示碳氢燃料/氧超临界燃烧火焰物理化学过程本质，为碳氢燃料/氧超临界燃烧技术发展提供重要的基础数据和理论支持。

The hydrocarbon fuel combustion problems of carbon deposit and combustion instability under extreme thermodynamic conditions in the development of advanced aerospace engines have become one of key scientific issues. At home and abroad, the fundamental research of hydrocarbon fuel/oxygen supercritical combustion is little. The research objective of the project is to explore the supercritical combustion characteristics of hydrocarbon fuel/oxygen laminar diffusion flow, the research on the flame structure and combustion stability under extreme thermal conditions is performed; combustion flame boundary characteristics, flame fine structure and morphological changes in the process are analyzed; the functional relationship between characteristic parameters of flame and combustion variables is established; the effects of combustion pressure and fuel flowrate on oscillation amplitude, wavelength and frequency are analysed; based on the measurement of flame temperature, soot and radical OH distributions, combined with the analysis of the hydrocarbon detailed reaction mechanism, the fine reaction functional partition structure of the hydrocarbon fuel/oxygen supercritical combustion flame is proposed, and chemical reaction mechanisms of the different flame partition are explored; the effects of cross diffusion on soot formation and flame structure are analyzed; the physical and chemical nature of hydrocarbon fuel/oxygen supercritical combustion flame is revealed. In the experimental and theoretical aspects,the project research provides the important basic data and theoretical support for the technology development of hydrocarbon fuel/oxygen supercritical combustion.