Technical Paper
A Deforming Droplet Model for Fuel Spray in Direct-Injection Gasoline Engines
2001-03-05
2001-01-1225
A three-dimensional numerical model has been developed to predict spray formation process of swirl or slit type injectors which are currently used in direct-injection gasoline engines. The Discrete Droplet Model (DDM) is totally enhanced: a new droplet deformation model is developed, which is theoretically introduced with a spheroidal shape assumption. The droplet drag model and droplet break-up model via Kelvin-Helmholtz and Rayleigh-Taylor instabilities are modified taken into account with the deformation. The break-up model parameters are dynamically changed according to a droplet Weber number. The model functions are developed using single droplet breakup measurement data. A liquid sheet injection and breakup models are incorporated into the DDM. A new parcel radius model is also introduced to get rid of the grid dependence of the droplet collision-coalescence model.