为了得到合理可靠和简化的反应机理,利用反应机理自动生成程序ReaxGen,构建了正庚烷、异辛烷、正癸烷和正十二烷的高温燃烧反应详细机理;同时分别采用物质产率分析和反应路径流量分析的方法对详细机理进行简化,得到了半详细机理和骨架机理。在较宽的温度和压力条件下,对半详细机理和骨架机理进行了点火延时、层流火焰传播速度和重要物种浓度曲线的模拟并与实验结果比较;最后,图示说明了这些烷烃的主要高温燃烧路径,给出了点火延迟时间的敏感度分析。结果表明:这些机理能够合理描述链烷烃的自点火特性,文中提出的结合ReaxGen程序的机理构建方法和反应路径流量分析的简化方法也可以用于其它烃类的高温燃烧机理构建。
Detailed chemical kinetic mechanisms were developed using the automatic mechanism generation software ReaxGen to describe the high-temperature combustion processes of n-heptane, n-decane, iso-octane, and n-dodecane, then semi-detailed and skeletal mechanisms were obtained using rate-of-production analysis and path flux analysis, respectively. Both the semi-detailed and skeletal mechanisms were validated against experimental ignition delay time, laminar flame speed, and the concentration profile of the important species over a wide range of temperatures and pressures. Final y, the major reaction pathways during the high-temperature combustion of these alkanes were illustrated using the reaction pathway analysis. Sensitivity analysis for ignition delay time was also carried out. The results indicated that the developed mechanisms provided a reliable description of the fuel auto-ignition characteristics, and therefore demonstrated that this method, which combines the ReaxGen and path flux analysis, could be used to reliably generate mechanisms for high-temperature combustion of other hydrocarbons.