Influence of dimethyl ether and diethyl ether addition on the flame structure and pollutant formation in premixed iso-octane flames

The aim of this study is thus threefold. First, a new species dataset for a pure iso-octane flame is reported, since speciation data under premixed flame conditions for this fuel is surprisingly scarce. Second, the effects of DME and DEE addition in increasing amounts to the iso-octane base flame are investigated with special attention to the flame structure and pollutant species formation. Third, a joint combustion model for iso-octane, DME, and DEE mixtures consisting of 379 species and 1931 reactions is proposed that was examined against the present data and reference experiments for a larger range of conditions. Key pathways of interesting species, including aldehydes, alkenes, and soot precursors were revealed with the present mixture model. DME and DEE addition were found to have a similar influence on the flame structure of iso-octane, except for some C2 and C3 intermediates. The addition of DME as well as of DEE decreases the formation of soot precursors while it enhances the production of formaldehyde.