Abstract
Comparison of heat release in low temperature reaction between normal-heptane and DME as a sub-fuel for iso-octane HCCI combustion was made by numerical analysis based on elementary chemical reaction model. From the analysis, it was shown that the minimum fuel quantity of DME necessary for iso-octane ignition was smaller than the case of normal-heptane, because the heat release from DME oxidation in the low temperature region is larger than that from n-heptane regardless of iso-octane quantities. In dual fuel HCCI combustion with a main fuel of iso-octane, the total heat release in low temperature region increases with increase in iso-octane quantity for both sub-fuel of normal-heptane and DME, unlike the case of a main fuel of methane or toluene.
