Fuel design for internal combustion engines has been proposed in our study. In this concept, the multicomponent fuel with high and low volatility fuels are used in order to control the spray and combustion processes in internal combustion engine. Therefore, it is necessary to understand the spray and combustion characteristics of the multicomponent fuels in detail. In the present study, the modeling of multicomponent spray vaporization was conducted using KIVA3V code.
The physical fuel properties of multicomponent fuel were estimated using the source code of NIST Mixture Property Database. Peng-Robinson equation of state and fugacity calculation were applied to the estimation of liquid-vapor equilibrium in order to take account for non-ideal vaporization process. Two-zone model in which fuel droplet was divided into droplet surface and inner core was introduced in order to simply consider the temperature distribution in fuel droplet. Furthermore, droplet diameter after breakup was optimized by changing the parameters in original TAB model, because original TAB model underestimated a droplet diameter.
The effects of fuel composition and initial fuel temperature on spray tip penetration, liquid droplet and vapor distribution, vapor mass and evaporation rate were investigated by using the multicomponent fuel spray model composed of these above sub models. From the numerical results, it was confirmed that the spray characteristics of multicomponent fuel drastically varied with a change in mixing fraction in multicomponent fuel and initial fuel temperature.