Homogeneous Charge Compression Ignition Combustion with Dimethyl Ether - Spectrum Analysis of Chemiluminescence

Homogeneous Charge Compression Ignition (HCCI) combustion with dimethyl ether has been carried out in a single cylinder engine with a transparent piston. The engine was operated at 800 rpm with a wide-open throttle. The intake-premixed mixture was preheated with an electric heater to promote auto-ignition. HCCI combustion with dimethyl ether indicates multi-stage heat releases. Investigations were conducted with visualization of combustion in the cylinder and detailed and temporal spectroscopic measurements using spectrometer. In order to understand reaction mechanism of auto-ignition and combustion mechanism in HCCI engine, spectrum analysis of chemiluminescence was carried out. Three main conclusions were drawn from this study. (1) Spectrum from chemiluminescence at low temperature oxidation was obtained successfully using developed optical fiber probe. (2) Emitting lights from HCHO according to Emeléous's cool flame bands appear at low temperature reaction. (3) During the main heat release, the CO-O recombination spectrum was strong. There was a strong correlation between rate of heat release and the CO-O recombination spectrum.