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Due to increasingly strict emission regulations for IC engines, there is a significant motivation to investigate the relevant physical processes with the objective to reduce the reduction of exhaust gas emissions. Spray characteristics play a progressively important role in the consequent processes of mixture formation, ignition, combustion and pollutant formation in direct injection diesel engines. It is also important to develop an understanding of the atomization qualities of alternative fuels such as Biodiesel fuels as potential substitutions for conventional diesel fuel. In this research, the effect of injection and ambient parameters on spray breakup and atomization of different alternative fuels are investigated using CFD simulation. An Eulerian-Lagrangian approach is implemented in order to study the interaction of the continuous and discrete phases.

Clean diesel engines are one of the fuel efficient and low emission engines of interest in the automotive industry. The combustion chamber flow field and its effect on fuel spray characteristics plays an important role in improving the efficiency and reducing the pollutant emission in a direct injection diesel engine, in terms of influencing processes of breakup, evaporation mixture formation, ignition, combustion and pollutant formation. Ultra-high injection pressure fuel sprays have benefits in jet atomization, penetration and air entrainment, which promote better fuel-air mixture and combustion. CFD modeling is a valuable tool to acquire detailed information about these important processes. In this research, the characteristics of ultra-high injection pressure diesel fuel sprays are simulated and validated in a quiescent constant volume chamber. A profile function is utilized in order to apply variable velocity and mass flow rate at the nozzle exit.