抄録
Detecting intermediate species existing between ignition stages is crucial to validate the detailed chemical mechanism for compression ignition depending on fuels. We have developed a pulse sampling method using direct species detection in a differential pumping system, by which HCHO, H_2O_2 etc. are detected in the crank-angle resolved manner. In this study, the effect of additives such as CH_3OH and O_3 to DME is evaluated with this method. It was confirmed that fuel consumption and HCHO formation in the cool ignition stage decrease with increasing addition of CH_3OH as predicted by Curran et al. DME 2000 mechanism. O_3 addition is confirmed to increase fuel consumption and heat release in the cool ignition stage, which accelerates the final hot ignition timing. The large coefficient of O_3 addition effect in the range under 100ppm addition was not observed in the experiments. The effect of residual gas is discussed as the reason of this discrepancy.
