Multidimensional Computations of Diesel Sprays in a Very High-Pressure Chamber

Department of Mechanical Engineering
University of Minnesota

Results of two and three-dimensional computations of non-combusting and combusting diesel sprays in a very high-pressure chamber were presented. A wide range of experimental conditions were considered.

Peak chamber pressure ranged from 0.4 Mpa to 20 Mpa. The spray model incorporated a line source for drops, heat, and mass and momentum exchange between the gas and liquid phases, turbulent dispersion of drops, collisions and coalescences, and drop breakup. Autoignition was modeled using an equation for a progress variable that represented the local instantaneous tendency of the fuel to autoignite. High-temperature chemistry was modeled using a local equilibrium model coupled to a combination of laminar and turbulent characteristic times. The accuracy of the models was assessed by making comparisons of computed and measured spray penetrations and chamber pressures. Reasonable agreement was obtained for a broad range of conditions.