高保真的简化或骨架反应机理对多维计算流体力学(CFD)燃烧模拟极其重要。首先,针对不同简化目标,使用包含误差传播和敏感性分析的直接关系图方法(DRGEPSA)通过简化主要参比燃料(PRF)详细机理,获得了一系列简化机理,发现简化机理的结构随简化目标的改变而显著不同;其次,基于不确定性定量化方法评估简化机理的性能,结果表明为避免简化机理的预测结果失真,需要在简化方法中使用较小的相对误差;最后,提出了解耦法的理论依据,并使用该方法构建PRF燃料的骨架机理。结果发现通过耦合详细H2/CO/C1子机理和骨架C4-Cn子机理,最终的骨架机理能够满意地预测滞燃期和火焰传播速度。
Reduced and skeletal mechanisms with high fidelity are urgently required for multi-dimensional computational fluid dynamics (CFD) combustion simulations. In this study, a sedes of reduced mechanisms were obtained by reducing a detailed mechanism of primary reference fuel (PRF) using the directed relation graph-aided error propagation and sensitivity analysis (DRGEPSA) method for different reduction targets. By analyzing the structures of the reduced mechanisms, it is found that the mechanism structure significantly changes with the variation of the reduction target. Then, the performance of the reduced mechanism is evaluated based on the uncertainty quantification. It indicates that a small relative error should be used in the mechanism reduction method to avoid distorted predictions from the reduced mechanisms. Finally, the decoupling methodology is proposed to construct the skeletal mechanism of PRF. The results show that both the ignition delay time and the laminar flame speed can be satisfactorily reproduced by the skeletal mechanism with a detailed H2/CO/C1 and a skeletal C,-Cn sub-mechanism.