Confined vortex rings in gasoline fuel sprays: modelling and observations

In a series of our earlier papers, basic properties of vortex ring-like structures in gasoline engines were interpretedin terms of the generalised vortex ring model. In the present paper, a model that can be regarded as a unifiedtheoretical framework for modelling of conventional vortex rings, confined vortex rings and confined vortex ringswith high Reynolds number (with elliptical core), is described. The range of validity of this model is investigatedbased on the comparison between the predictions of the model and the results of Direct Numerical Simulations(DNS). The results of the study of a two-phase vortex- ring flow based on the conventional vortex ring modeland Fully Lagrangian Approach (FLA) are presented. Two flow regimes corresponding to two initial conditions areinvestigated: injection of a two-phase jet and a vortex ring propagating through a cloud of particles. In both casesthe ranges of governing parameters leading to the formation of mushroom-like clouds of particles are identified.Modelling results are compared with experimental observations where possible.