Modelling of Breakup Processes in Transient Diesel Fuel Sprays

This project is concerned with the development of new mathematical models for transient Diesel fuel jets, taking into account their instabilities and acceleration, in a form suitable for implementation into computational fluid dynamics (CFD) codes.

The distinction between convective, absolute and global instabilities and the effects of cavitation on the formation of Diesel fuel sprays will be taken into account. The latter effects are expected to appear via the modification of the boundary conditions for jets at the exit of the nozzle. Effects of boundary disturbances on the breakup of the jet will be studied experimentally using a three dimensional laser vibrometer. The jet acceleration is expected to lead to partial stabilisation of the jet.

The effects of jet acceleration and jet instabilities will be used to develop a new stochastic model for the primary spray breakup in a form suitable for implementation into CFD codes. This stochastic model will be implemented into a customised in-house version of the KIVA-2 CFD code. This code will be used for modelling fluid dynamics, heat transfer and combustion processes in Diesel engines. The results of the modelling will be validated against in-house experimental data. This will open the way to implement new models to other CFD codes, including commercial ones.