Jet and Vortex Ring-Like Structures in Internal Combustion Engines: Stability Analysis and Analytical Solutions

Recently developed models, describing the disintegration of liquid jets and the dynamics of vortex ring-like structures at Die- sel and gasoline engine-like conditions, are reviewed. The results of comparative analysis of modal and non-modal hydrody- namic instabilities of round viscous fluid jets are presented. Analytical formulae for vortex ring translational velocities, pre- dicted by vortex ring models, are compared with the results of numerical solutions to the underlying equations and experimen- tal data. A new approach to numerical simulation of two-phase two-dimensional flows, based on a combination of the full La- grangian method for the dispersed phase and the vortex blob method for the carrier phase, is discussed.