Abstract
Homogeneous Charge Compression Ignition (HCCI) combustion and effective use of gaseous fuels have attracted much interest as means of obtaining cleaner exhaust gas with a lower carbon content from internal combustion engines. In this study, the effects of the fuel type on ignition, combustion and engine performance characteristics were investigated experimentally and by chemical kinetic simulations using blended fuels of dimethyl ether (DME) and methane or DME and propane. The results showed that the blended fuel of DME and methane produced two-stage primary combustion, depending on the operating conditions, which had the effect of moderating combustion. With the blended fuel of DME and propane, ignition was delayed, making it possible to moderate the rapidity of primary combustion. It was also observed that propane had a larger effect than methane on suppressing the low-temperature oxidation reactions of DME.
