燃烧反应机理全局性简化及骨架机理优化

There exist uncertainties in the reaction rate coefficients of combustion mechanisms,which will affect the contribution of different reactions to the combustion characteristic parameters.Moreover,these uncertainties will also influence the statistics of contributions by different species in the reactions when the reduction method based on relation graph is employed,causing the coupling degree between species to be uncertain.In the present work,the combustion mechanism is simplified and optimized with the consideration of uncertainties in the reaction rate coefficients.First,1000 possible detailed mechanisms are obtained by uniform sampling in the uncertain parametric domain of rate coefficients.Then,the directed relation graph(DRG)method is applied to simplify these detailed mechanisms,and the removed species are counted and ranked.Finally,the model is reduced according to the probability.In addition,the global sensitivity analysis(GSA)method is applied to identify the key reaction in the skeletal mechanisms,and those with higher sensitivity are further optimized.In this way,the simplified mechanism with higher prediction accuracy can be obtained.