Development of the full Lagrangian approach for the analysis of vortex ring-like structures in disperse media: application to gasoline engines

As vortex ring-like structures in two-phase mixtures occur in a wide range of systems such as gasoline engines, appropriate mathematical models of such processes would allow engineers to rapidly test novel ways of optimising and improving a range of engineering systems before resorting to costly experimental evaluation of new technologies. This proposal is therefore concerned with the generalisation of a mathematical approach known as the full Lagrangian approach (also known as the Osiptsov-Lagrangian method) to enable it to model vortex ring-like structures in two-phase mixtures. The main focus of the project is on the development of this approach to enable its use in the modelling of three-dimensional processes within a Computational Fluid Dynamics (CFD) framework. The project will also investigate the possibility of constructing new mathematical models of vortex ring-like structures, to take into account additional complications relevant to certain engineering applications such as the effect of an elliptical core. This new approach to the modelling of multiphase flows incorporates the jet and droplet break-up models developed through a currently active EPSRC project EP/F069855/1. Where appropriate, predictions resulting from the new models are compared with predictions based on three dimensional numerical simulations of transient vortex ring-like structures, based on the conventional research CFD code KIVA 3 and commercial CFD code ANSYS FLUENT. A feasibility study is also performed into the modelling of these vortex ring-like structures based on the combination of the full Lagrangian approach for the dispersed phase and the vortex method for the carrier phase to examine the advantages and limitations of the different mathematical approaches. Finally, predictions from numerical and analytical models have been validated against in-house experimental results obtained in gasoline engine-like conditions allowing an assessment to be made into the applicability of using the models for the characterisation of processes in gasoline engines.