Abstract
In the present study, we proposed a novel fuel design concept in order to achieve low emissions and combustion control in engine systems. The fuel design concept is based on the combustion control that could be realized by using a mixed fuel consisting of a lower boiling point (b.p.) fuel and a higher b.p. fuel as shown in figure A. Mixing of n-pentane (low b.p. fuel), a gasoline component, with n-tridecane (high b.p. fuel), a gas oil component, was the selected fuel design concept of this study. The spray evaporation process of the mixed fuel was analyzed using planar laser-induced fluorescence (PLIF) and Mie scatter imaging. Vaporization of the mixed fuel is promoted through the occurrence of a two phase region. Additionally, combustion experiments were conducted inside a rapid compression and expansion machine (RCEM) in order to confirm combustion and exhaust constituent properties. The ignition delays for several mixture mole fractions obtained from the heat release profiles are presented in figure B. In the case of single component fuels having the same transport properties of mixed fuels, the ignition delay linearly increases with decreasing carbon number. However, in the case of the mixed fuels, it is confirmed that, compared to pure fuels of the same mean carbon number, ignitability is improved, even though the high ignitability fuel (n-tridecane) is diluted by the low ignitability fuel (n-pentane).
