Untersuchung der innermotorischen Einflussgrößen auf die Partikelemission eines Ottomotors mit Saugrohreinspritzung

Abstract

This research work comprises experiments intending to understand the particulate formation mechanisms of spark ignition (SI) engines with port fuel injection (PFI) as well as the analysis of measures to enhance the mixture formation process in order to reduce particulate number emissions (PN). Basic investigations were performed in an evaporation box, which was designed in the shape of a real intake port. This way not only the evaporation characteristics of different sprays but also the spay-wallinteraction could be evaluated. It is known that fuel wall films are a major source for particulate formation. High-speed images were acquired to analyse and minimize wall fuel films within the combustion chamber of a motored transparent engine using a glass cylinder. This way wall fuel films could be visualized and quantified by means of their surface area. A number of different parameters influencing the emission of PN was investigated on a four-cylinder research engine, which is optically accessible through endoscopes in both the combustion chamber as well as the intake manifold.