Simulation of Liquid NH3 Spray Characteristics for Gasoline Direct Injection (GDI) under Engine-Relevant Conditions

Fuel/air mixing characteristics of liquid ammonia under direct injection engines have gained significant attention in the automotive industry due to their potential for improving fuel efficiency and reducing emissions. This study employed a simulation approach to investigate the spray characteristics of liquid ammonia for Gasoline Direct Injection (GDI) under Engine-Relevant Conditions. Conversely, lower injection pressures resulted in shorter spray penetration due to reduced fuel momentum and weaker atomisation. The main variable in this study is injection pressure, which is 50 bar, 80 bar and 110 bar. Meanwhile, the parameters for the orifice diameter used in the CFD simulation by Ansys Fluent are 0.3 mm and the ambient pressures, which are atmosphere pressure and the other hand, remain constant throughout the research. The simulation results showed a clear relationship between injection pressure and spray penetration. Higher injection pressures increased spray penetration, indicating improved fuel dispersion and atomisation. This is attributed to the higher kinetic energy of the fuel, leading to enhanced breakup and smaller droplet sizes.