A nonlinear atomization model for computation of drop size distributions and spray simulations

A model has been developed to provide a comprehensive simulation of a spray formed by a high-speed liquid jet. The primary atomization process is simulated in a completely nonlinear fashion using the boundary element method under the assumption of axisymmetric, inviscid flow. The presence of the orifice boundary layer is simulated with a ring vortex whose strength and location are uniquely determined from boundary layer properties at the orifice exit plane. Droplet and axisymmetric ligament tracking models have been developed to provide more comprehensive spray simulations. The breakup of the axisymmetric ligaments shed from the parent surface is assessed both in a nonlinear fashion as well as using the linear stability analysis of Ponstein. Using this latter approach, drop size distributions have been generated from first principles and compared with the popular Rosin-Rammler model.