Computation of NO Levels for Various Operations in SI Engines

Abstract

The method of computation is proposed to estimate NO emission levels of spark ignition engines operating with not only homogeneous but also nonhomogeneous mixtures, because mixture states other than a homogeneous one may deliberately be used to improve pollutant emissions and engine performance. First proposed is a model valid for homogeneous mixtures, and then it is so modified as to be applicable to various nonhomogeneous mixtures such as a stratified charge. These models allow us to survey the relation between NO emissions and the variations of mixture states or operating conditions in SI engines.