中文摘要：

C3H8是液化石油气（LPG）的主要成分，其火焰结构的数值预测对于消防等相关行业具有重要意义。单步或总包反应过于简单，不能描述碳氢燃料的氧化机制，而耦合燃料详细机理的燃烧模拟计算量大，且描述反应的数学系统具有极强的“刚性”，限制了反应机理的实际应用，而去除冗余反应和组分的简化机理具有描述燃烧的全面性优点，且降低了数学系统的“刚性”，因此耦合简化机理的火焰结构数值预测具有优势。本文采用基于矩阵分析的主成分（PCA）分析技术，分析研究了wang等发展的469步C3H8详细反应动力学机理，获得了组分的重要性排序，基于此分别构筑了320步和214步两个简化机理，针对典型扩散火焰的计算，表明建立的两个简化机理具有较高的模拟可靠性，同时也提供了一种框架简化机理的构筑方法。

英文摘要：

C3H8 is one of the major species of Liquefied Petroleum Gas（LPG）. It＇s important to the industrial sector such as fire department that the numerical prediction of the flame structure for C3H8. One step or the global reaction is so simple that it can＇t describe the oxidation mechanism of hydrocarbon fuels. But coupling simulation of the detailed mechanism for combustion is very complex. And the description of the mathematical system has a very strong ＂stiffness＂. It limits the practical application of the reaction mechanism. The reduced mechanism with no redundant reactions and species has advantages of depicting the combustion comprehensiveness. Furthermore, it lowers the ＂stiffness＂ of the mathematical system, The numerical prediction coupling with reduced mechanism has many advantages. The method of principal component analysis based on the Jacobian matrix was conducted to the 469-step detailed mechanism of C3H8 which had been developed by Wang and others. Two reduced mechanisms consisting of 320 and 214 reactions were conducted through sorting the important species. The numerical calcula- tions for typical diffusion flame showed that the two reduced mechanisms had higher reliability of the simulation. Simultaneously, a constructing method of skeletal reduced mechanism was developed in the paper.