MODELING OF MULTI-COMPONENT DROPLET COALESCENCE IN EVAPORATING AND NON-EVAPORATING DIESEL FUEL SPRAYS

A new coalescence model for droplets with different mixture composition is developed and implemented in spray calculations. This model is based on an extension of Brazier-Smith et al.'s model (1972) for two colliding droplets with different densities. Based on the rotational kinetic and surface energies of a system of two droplets, coalescence efficiency for two colliding droplets with different densities is formulated. In the case of grazing collision, the effect of density of droplets is also included. The new droplet coalescence model is examined for evaporating and non-evaporating diesel sprays. Validation studies were carried out for both cases and the results were compared with available experimental data. The model shows good predictive capability and was demonstrated to improve the accuracy of multi-phase flow simulations.