Development and evaluation of a manifold projection trajectory-based method for combustion mechanism reduction of fuel

The computational fluid dynamics model coupled with skeletal mechanism proves to be an effective approach for engine combustion simulation. To generate a reliable and compact skeletal mechanism, a manifold projection trajectory-based method (MPT) was developed and rigorously evaluated in this study. By comparing predicted combustion characteristics such as ignition delay time, laminar flame speed, and PSR temperature by detailed and skeletal mechanisms of ethanol, methyl butanoate, and diesel surrogate fuel, it is demonstrated that the MPT method allows for substantial scaling down of both single-component and multi-component fuel mechanisms while preserving an acceptable level of accuracy. For multi-component fuel, the skeletal mechanisms by MPT are independent of the mixture composition. To further portray the prowess of MPT, a comparative analysis was conducted using n-dodecane as a case alongside traditional mechanism reduction methods, including directed relation graph with error propagation and sensitivity analysis (DRGEPSA) and path flux analysis (PFA). The findings reveal that MPT exhibits superior performance in terms of the size of the generated skeletal mechanisms and their accuracy in predicting combustion behaviors.