Search Results

Detailed investigations on wall film behavior in port injected SI engines show that a standard UEGO sensor leads to inaccurate results during transients concerning the real air/fuel ratio. Purpose of this paper is to identify the reasons for this behavior and developing a compensation strategy. Fuelling transients due to steps in the injection period at constant engine speed and MAP with modified sensors were carried out and the influence of the protective tube and the dynamic behavior of the measuring cell were found to be the essential parameters. The standard UEGO sensor can be used to determine the air/fuel ratio during transients, if the reasons for inaccurate results presented in this paper are considered.

This paper reports an investigation of the particle size distribution of different homogeneous Diesel combustion systems in comparison to conventional diffusion controlled combustion system. The influence of different operating parameters such as load or degree of homogeneity on the number of particles and the particle size distribution, determined with a Scanning Mobility Particle Sizer, is pointed out. The homogeneous combustion of Diesel fuel possesses a large potential concerning NOX, soot and particle mass, but still a high number of nanoparticles is discharged. Additional experiments are reported, which were carried out to understand the high emission of nanoparticles at low soot combustion better and to determine the chemical composition of the nanoparticles.