基于组分半全局敏感性的燃烧反应动力学模型简化方法

Chemical Kinetic Model Reduction Through Species-Targeted Semi-Global Sensitivity Analysis

针对目前缺乏对燃烧反应动力学机理中组分重要性判别的诊断方法,本文提出可准确量化组分重要性的半全局敏感性分析方法,并应用此方法简化USCMechII、JetSurF和DME机理,得到的简化机理可分别精确预测乙烯、正庚烷和二甲醚的点火延迟时间.基于组分半全局敏感性方法不仅可以精确评价组分的重要性程度,还可以分辨组分的正负贡献;采用此方法消除不重要的组分,最终得到32组分的乙烯燃烧机理、56组分的正庚烷燃烧机理和32组分的二甲醚氧化机理,并且这3个简化机理也比通过DRG和DRGEP方法得到的简化机理更加紧凑.

In view of the lack of diagnostic methods for evaluating the importance of species in kinetic combustion mechanisms,a species-targeted semi-global sensitivity analysis method is proposed to evaluate the importance of species and simplify chemical models.The proposed method is used to reduce the USCMechII and JetSurF mechanisms and Wang’s model for dimethyl ether(DME),so that the reduced mechanisms can accurately predict the ignition delay time of ethylene,n-heptane and DME,respectively.The species-targeted semi-global sensitivity method can not only evaluate the importance of species but also reveal the positive and negative contributions of species to combustion properties.With unimportant species eliminated by this method,USCMechII for ethylene oxidation,JetSurF for n-heptane oxidation and Wang’s model for DME oxidation are reduced to skeletal mechanisms consisting of 32,56 and 32 species,respectively.And these reduced mechanisms are more compact than those obtained by the directed relation graph(DRG)method and the directed relation graph with error propagation(DRGEP)method.