Droplet dynamics in a vortex-ring flow

Fuel consumption targets and exhaust gas emissions legislation have focussed automotive engineers to investigate new strategies for liquid fuel injection. In one of these concepts, the mixture preparation process is governed by spray vortex ring-like structures in the combustion chamber, close to the spark plug gap. The liquid fuel exits the nozzle and accelerates the surrounding gas forming mushroom-like patterns of various sizes. This type of flow is typical for direct injection combustion systems. In [1] the vortex ring-like structures in gasoline fuel sprays were studied experimentally and the results were compared with the analytical model for a classical vortex ring flow (single phase flow) suggested in [2]. The purpose of the current study is to investigate droplet distribution in a two-phase vortex-ring flow typical for gasoline engines.