提出了一套系统化多级机理简化策略,包含基于误差传播的直接关系图法、峰值浓度分析法、线性同分异构体集总法、主组分分析法、温度敏感性分析和产率分析法,并将其应用于汽油四组分表征燃料详细反应机理的简化,构建了适用于HCCI发动机燃烧边界下的简化机理模型,包含149个物种、414个反应。通过与激波管、快速压缩机、增压HCCI发动机实验数据的对比验证表明,新机理可以准确地预测较宽范围条件下的着火滞燃期,在HCCI发动机的单区模型计算中,该机理对缸内燃烧和排放的预测结果是令人满意的。放热率分析表明, R + O2反应是控制中间温度区放热的关键基元反应,在高压低温下,异辛烷的放热起到决定性作用。添加2-戊烯之后,使得四组分模型相较于三组分模型更为准确,尤其是对于第一阶段着火滞燃期有显著影响,为进一步探索调和燃料组分比例控制HCCI燃烧提供了一条新思路。
Asystematic multi-stage mechanismreduction strategy for performing skeletal reductions of gasoline four-component surrogate fuel is presented. The approach includes the directed relation graph with error propagation, peak concentration analysis, linear isomer lumping, principal component analysis, temperature sensitivity analysis and rate of production analysis. The final reduced mechanism comprises 149 species and 414 reactions with embedded cross-reactions, which is suitable for homogeneous charge compression ignition (HCCI) engine application. Comparisons between computational and experimental data including the shock tube and rapid compression machine, indicate that the new reduced mechanism can provide good predictability of the ignition delay over extensive parameter space. Applying the reduced mechanism to the HCCI single zone model also shows satisfactory combustion and emission characteristics of the boosted HCCI combustion. Further heat release analysis demonstrates that R + O2 are the key reactions controlling the intermediate temperature heat release and under high pressure and low temperature conditions, iso-octane is the most important species resulting in a large portion of heat release. After the addition of 2-pentene, the new four component model displays better predictability than the three component model, especially relative to the firststage ignition delay. Based on these new findings, we can use different composition ratios to arbitrarily control the combustion phasing of HCCI combustion