Modeling of Auto-Ignition and Combustion Processes for Dual-Component Fuel Spray

Auto-ignition and combustion processes of dual-component fuel spray were numerically studied. A source code of SUPERTRAPP (developed by NIST), which is capable of predicting thermodynamic and transportation properties of pure fluids and fluid mixtures containing up to 20 components, was incorporated into KIVA3V to provide physical fuel properties and vapor-liquid equilibrium calculations. Low temperature oxidation reaction, which is of importance in ignition process of hydrocarbon fuels, as well as negative temperature coefficient behavior was taken into account using the multistep kinetics ignition prediction based on Shell model, while a global single-step mechanism was employed to account for high temperature oxidation reaction. Computational results with the present multi-component fuel model were validated by comparing with experimental data of spray combustion obtained in a constant volume vessel. The results showed a good agreement in terms of spray tip penetration, liquid length, ignition delay and so on, for several kinds of dual-component fuels. Additional investigation into a combustion control methodology using dual-component fuel, which aims to mitigate combustion rate of premixed charge, was performed. Consequently, the feasibility of this approach was confirmed.