Abstract
Direct injection spark ignition gasoline engines have shown increased particulate matter emissions in cold start conditions due to the pool combustion of the wall fuel films. Hence, further understanding of the in-cylinder pool combustion is required. In previous studies, we devised an experimental model that reproduces sooting characteristics of in-cylinder pool combustion as a steady phenomenon using an opposed-flow burner. In this study, we investigated the effect of butanol addition to iso-Octane/Toluene blends on sooting behavior. Experiments were conducted using four isomers of butanol as alcohol fuel and replacing a part of iso-Octane with them. As results, it was shown that the experimental values of PVF were the maximum at a slightly lean equivalence ratio of pre-mixture. The maximum PVF equivalence ratio did not change depending on the kind of blended alcohols. s-Butanol and n-Butanol had a large effect on soot reduction, and i-Butanol and t-Butanol did not show sufficient effect.
