采用自定义阈值的计算奇异扰动在构建二甲醚简化机理上的应用

将自定义误差阈值的计算奇异扰动(CSP)应用于包含55种物质和290步反应的二甲醚的详细机理上,构建了包含26种物质和20步反应的简化机理.开发了一套基于该算法的计算机程序--I-CSP.程序的输入数据包括:① 详细的反应机理;② 在Chemkin中计算的结果;③ 准稳态物质的数量.然后,将简化机理在均匀的反应器(包括自燃反应器和完全搅拌器)中进行验证.结果发现,计算结果与详细机理相比符合得相当好; 但当在非均匀反应器(一维、稳态、自由扩展预混合火焰)中验证时,结果显示出一定偏差.

A Criterion Based on Computational Singular Perturbation for the Construction of Reduced Mechanism for Dimethyl Ether

A criterion based on computational singular perturbation (CSP) was proposed to determine the number of quasi-steady state (QSS) species. Together with CSP, it was applied to the reduction of dimethyl ether (DME) involving 55 species and 290 reactions leading to the development of a 26-species reduced mechanism with 20 lumped steps. A software package named I-CSP was developed to make the reduction process more efficient. Input to the I-CSP includes (i) the detailed mechanism, (ii) the numerical solution of the problem for a specific set of operating conditions, (iii) the number of quasi steady state (QSS) species. The resulting reduced mechanism was validated both in homogenous reactor, including auto-ignition and PSR, over a wide range of pressure and equivalence ratio, and in a steady, one-dimensional, burner-stabilized freely propagating premixed laminar flame. Comparison of the results calculated with the detailed and the reduced mechanisms shows excellent agreements in homogenous reactor, but discrepancies can be observed in the premixed laminar flame.