Combustion chamber wall influences on the vaporisation, mixture formation and combustion in DI diesel engines with a small combustion chamber

Abstract

In direct injection passenger car diesel engines with a small displacement and a small combustion chamber, the short distance between the injection nozzle and the wall of the combustion chamber can cause operating conditions which display an intense contact between the fuel and the combustion chamber wall. The interaction between the liquid phase and the wall significantly influences the mixture formation, the combustion and consequently the formation of exhaust gases. During a research project which was carried out in a cooperation between the Lehrstuhl für Technische Thermodynamik (LTT) of the Universität Erlangen-Nürnberg and the Lehrstuhl für Verbrennungsmotoren of the Universität Dresden (LVD), injection, vaporisation, combustion and emission behaviour were analysed using conventional, electronic and optical measurement techniques in basic investigations and under engine-realistic conditions. In Part 1 of this report, the results of the investigations carried out inside an optically accessible high-pressure hightemperature injection chamber were discussed. Part 2 presents the results of the investigations carried out by the LTT Erlangen and the LVD Dresden on a series production engine and on an optically accessible engine.