Atomisation, Ignition and Mixing In New Generation DIESELS (AIMING-DIESELS)

An increased market share by Diesel-powered automobiles has allowed the automotive industry to meet the legislated future reduction of fleet-average C02 emissions by more than 50%, but Diesel engines at the time of the project did not meet future legislation for NOx and particulate emissions.

A new generation of engine design was required, which would be based on high injection pressures and intelligent injection schedules, and the proposed research would contribute to the understanding of the key processes of Atomisation, Ignition and Mixing of liquid fuel and vapour (AIM).

A step change in the understanding of AIM was proposed, resulting from measuring in an internationally unique experimental facility, allowes study of injection at real engine pressure and temperature at top dead centre (TDC) corresponding to supercritical conditions for the Diesel fuel.

Innovative instrumentation was developed which, together with carrunt state-of-the-art instrumentation, quantified AIM in a Diesel spray, in terms of crank-angle-averaged vapour concentration at ignition locations, correlated with spray characteristics and in-flame soot levels for a range of injection schedule, injection pressure, TDC temperature and pressure, and Exhaust Gas Recirculation (EGR) conditions, corresponding to extreme emission conditions for NOx and particulates as determined from engine data.

In a project uniting the University of Brighton with partners Ricardo and Delphi Diesel, a phenomenological model resulted for AIM for supercritical conditions, which assisted in providing suggestions for improved computational models and determining the operating conditions for optimum performance of engines.