AN APPROACH TO MODELING FLASH-BOILING FUEL SPRAYS FOR DIRECT-INJECTION SPARK-IGNITION ENGINES

Flash-boiling is a phenomenon which occurs when a liquid is discharged into an environment with an ambient pressure below the saturation pressure of the liquid. The present computational work provides an approach to modelling flash-boiling fuel sprays using the Lagrangian particle tracking technique. An atomization model based on heterogeneous nucleation inside the nozzle is implemented as a boundary condition at the nozzle exit and alongside a superheat evaporation model for the emerging spray droplets. The near-nozzle dense spray region of flash-boiling sprays is also investigated by consideration to the initial spray plume cone angle. The model was able to predict important flash-boiling phenomenon such as spray collapse and droplet recirculation automatically, validated against experimental data.