A Mechanism Reduction Method Integrating Path Flux Analysis with Multi Generations and Sensitivity Analysis

A novel mechanism reduction method that integrates path flux analysis with multi generations and sensitivity analysis (MPFASA) is proposed to reduce the complex detailed chemistry and to generate skeletal mechanisms. At first, the path flux analysis with multi generations (MPFA) method is used to efficiently reduce detailed mechanisms; then the sensitivity analysis (SA) method is applied to further eliminate the redundant species and their related reactions on the basis of the skeletal chemistry obtained by the MPFA method. Detailed mechanisms of methane and <i>n</i>-heptane are reduced by the MPFASA method, which are validated in the context of autoignition and perfectly stirred reactor for methane/air and <i>n</i>-heptane/air mixtures, over a wide range of operating conditions. The comparison shows that the skeletal mechanisms generated by the MPFASA method can well reproduce the results of detailed mechanisms and contain a much smaller number of species and reactions than those obtained by using the MFPA method only. It is illustrated that the MPFASA approach can overcome the shortcomings of the MPFA and SA methods and can be applied to obtain further reduced skeletal mechanisms in reactive flow modeling.

本文提出了一种集成多代路径通量分析（path flux analysis with multi generations, MPFA）与敏感性分析（sensitivity analysis, SA）的新型机理简化方法（MPFASA），用于简化复杂的详细化学机理并生成骨架反应机理。首先，采用多代路径通量分析（MPFA）方法实现详细机理的高效简化；随后，基于MPFA方法得到的骨架化学机理，通过敏感性分析（SA）进一步剔除冗余组分及其关联反应。研究采用MPFASA方法对甲烷与正庚烷的详细化学机理进行简化，并针对甲烷/空气、正庚烷/空气混合物，在宽工况范围内的自燃及全混流反应器场景下对简化所得的骨架机理开展验证。对比结果表明，MPFASA方法生成的骨架机理能够精准复现详细化学机理的计算结果，且相较于仅采用MPFA方法得到的骨架机理，其包含的组分与反应数目显著更少。研究表明，MPFASA方法能够克服MPFA与SA单一方法的局限性，可应用于反应流动建模中以进一步获取精简后的骨架反应机理。