正庚烷复杂化学框架与全局简化机理构筑

Constructions of Skeletal and Global Reduced Mechanisms for n-Heptane Complex Chemistry

基于误差传播的直接关系图法(DRGEP),针对正庚烷复杂化学,成功地进行了指定精度的不同水平框架机理简化研究.精确地查明了指定组分的依赖关系,构造出仅包含重要化学路径的动力学机理.分别给定阈值ε为0.01和0.001,获得的框架机理分别包含690和398个反应、涉及69和52种组分,虽然给定阈值的精度并不高,但所得框架机理和原复杂化学关于火焰结构的计算吻合很好.为了进一步增加简化度,采用了全局简化机理构筑的延伸算法,增加了算法的通用性,同时基于CSP分析,确定了QSS组分,在已建立的框架机理的基础上,进一步构筑了30和20组分全局简化机理,计算结果表明,2个全局简化机理仍具有很高的模拟精度.

The method of error-propagation-based directed relation graph（DRGEP） was conducted to the reduction of detailed reaction mechanism to the level of skeletal mechanism of n-heptane with specified accuracy.A geometric error propagation strategy applied to this graph accurately identifies the dependencies of specified targets and creates a set of increasingly simplified kinetic schemes containing only the chemical paths deemed the most important for the targets.Two skeletal mechanisms consisting of respectively 69 species involved 690 reactions and 52 species involved 398 reactions with identified threshold value being 0.001 and 0.01 for n-heptane oxidation,was found to mimic the performance of the detailed mechanism with high fidelity.It was found that the algorithm developed for the construction of reduced mechanisms is formally valid when the accompanying relations among the elementary reaction rates are associated with steady state assumptions.An extension of the algorithm was used which can accommodate more general relations.Based on this algorithm,the 30-and 20-species global reduced mechanisms developed was further reduced by CSP to identify the QSS species.High fidelity in simulation was again demonstrated.