Analysis of Two-Component Fuel Spray with Multicomponent Fuel Model under High Pressure Injection Conditions

<p>In compression ignition engines, the physical and chemical properties of the fuel are important factors that governed the formation of the air fuel mixture and the subsequent combustion process¹). Our study has proposed a concept of fuel design in which a fuel with a high boiling point is mixed with a fuel with a low boiling point as a spray control method for low emission and combustion control in engine systems. A multicomponent fuel model was proposed to estimate the vapor-liquid equilibrium and physical properties of the mixed fuel, and a two-component fuel spray feature was analyzed using the KIVA code. However, in the previous studies, the maximum fuel injection pressure was set on 15 MPa, and the analysis for high injection pressures in recent diesel sprays has not been performed. In this study, a multicomponent fuel model was used to analyze a two-component fuel spray under high injection pressures, and a large difference was observed between the experimental results of liquid core length and the calculation results. In the analysis, the MTAB model, which models the breakup phenomenon of fuel droplets in low Weber number region, was used as the breakup model, and it is considered necessary to use a breakup model that analyze the breakup behavior in high Weber number region as the fuel injection pressure increases. In this study, the behavior of multicomponent fuel sprays was analyzed by using the WAVE-MTAB model, which models the breakup phenomenon of diesel sprays under high fuel injection pressure conditions²). The spray tip penetration and the spatial distribution characteristics of each component fuel were verified. As a result, as Figure 1 shows that the higher boiling point fuel in a two-component fuel spray injected at high pressure is mainly distributed in the tip of the spray than the lower boiling point fuels.</p>