Abstract
This research examined the influence of the mixture ratio of a blended fuel on the combustion characteristics of a homogeneous charge compression ignition (HCCI) engine. The test fuel used was a blend of dimethyl ether (DME) and methane. The heat release rate was analyzed and flame light was observed by spectroscopy in experiments conducted at an equal injected heat value and identical ignition timing. It was found that mixing in methane extended the combustion duration and resulted in the disappearance of light emission corresponding to the OH radical in the latter half of the combustion period.
