Befrui, B. and D'Onofrio, M., "Primary Atomization of a GDi Multi-Hole Plume Using VOF-LES Method," SAE Technical Paper 2014-01-1125, 2014, doi:10.4271/2014-01-1125.
This study is concerned with quantitative analysis of the primary atomization, regarding the droplet size-velocity distribution function, of a multi-hole GDi plume through application of the Volume-of-Fluid Large Eddy Simulation (VOF-LES) method. The distinguishing feature of this study is the inclusion of an accurate seat /nozzle flow domain into the simulation.A VOF-LES study of the seat-nozzle flow and the near-field primary atomization of a single plume of a GDi multi-hole seat is performed. The geometry pertains to a purpose-built 3-hole GDi seat with three identical flow hole and counter-bore nozzles, arranged with 120° circumferential spacing.The VOF-LES prediction of the jet primary breakup structure and near-field macroscale is compared with spray imaging data. The droplet size and velocity distributions within a 4mm vicinity of the nozzle are analyzed. The results show production of a wide droplet size distribution through the jet primary atomization. Analysis of the droplet-size probability function, through comparison with the jet turbulence and Kelvin-Helmholtz parameters, indicates the dominant role of jet turbulence in the primary breakup process.The simulation results, in the form of the droplet size probability function and the joint droplet size-velocity distribution function, enable a complete description of the plume initial conditions for Lagranagian spray simulation.