多成分燃料の噴霧挙動に関する研究 : 第3報, LIF法を用いた多成分燃料噴霧における蒸気分布の観察

The objective of this study is to analyze effect of fuel properties on vaporization behavior and each component's vapor distribution in multi-component fuel. In this study vaporization characteristics of multi-component fuel were investigated by LIF methods. A pulsed Nd-YAG laser was used as a light source. The experiment is conducted in a constant-volume vessel with optical access. Fuel is injected into the vessel with electronically controlled common rail injector. Tested fuel contains i-octane (C8H18), n-dodecane (C12H26) and n-hexadecane (C16H34) that are selected as low-, middle-and high-boiling point fuel, respectively. Experiment conditions are 42 MPa, 72 MPa and 112 MPa in injection pressure, 15 kg/m3 in ambient gas density, 700 K in ambient gas temperature, and different fuel mass fraction. Spatial distribution of each component's vapor and fuel mixing process were assessed on the LIF images. And homogeneity of fuel vapor is discussed using the entropy analysis. Experimental results show that fuel vapors are distributed to stratification, and diffusion comes active with increase of mass fraction of low boiling point component.