The Role Of Mean Motion and Turbulence structure on Gaseous and Particulate Emissions of D. I. Diesel Combustion System

The status of the research carried out at the Istituto Motori aimed to optimize the direct injection light duty combustion system with regard to pollutant emissions is described. The influence of combustion chamber design on air flow field was investigated by means of a two colors LDA system as well as by engine test bed.

Three-dimensional computer simulations of injection and in- cylinder air motion have been run in order to analyze some experimental results.

In particular two configurations of axisymmetric combustion chambers were examined and, results were compared with those obtained from a four-lobe microturbulence combustion chamber.

Tests showed that some improvement in the NOx-particulate trade off can be obtained at part load at both high and low speeds.