二甲醚燃烧机理的简化及其均质压燃燃烧验证

Simplification of DME Combustion Mechanism and Validation with HCCI Combustion

基于积分计算奇异摄动法简化了二甲醚骨架机理,构建了包含24种物质和20个反应的二甲醚简化机理,并采用发动机单区模型进行验证.结果表明:所提出的二甲醚简化机理具有Curran等提出的详细机理的低温反应、负温度系数区、甲酸生成与消耗过程、高温反应等特征,而且与Curran等提出的详细机理的计算结果较吻合,表明其适用于二甲醚均质压燃过程的模拟计算;利用重要性因子进一步"修剪"后的二甲醚简化机理的适用性较差,表明原二甲醚简化机理的简洁度较高.

Based on the integration computational singular perturbation （ICSP）, a reduced mechanism consisting of 24 species and 20 reactions was simplified from the skeletal mechanism. The reduced mechanism was validated using closed internal combustion engine simulator, and it was found that the reduced mechanism reproduced the important characteristics of dimethyl ether （DME） detailed chemical kinetic model, such as low temperature reaction, negative temperature coeffcient （NTC）, the production and consumption of HCOOH and high temperature reaction. The results calculated from the reduced mechanism agree with that from the detailed one, which means that the reduced mechanism is suitable for the numerical simulation of homogeneous charge compression ignition （HCCI） fueled with DME. Besides, the poor applicability of reduced mechanism after trimmed by important index iuustrates the high simplicity of original reduced mechanism.