The Influence of Overall Equivalence Ratio and Degree of Stratification on the Fuel Consumption and Emissions of A Prechamber, Stratified-Charge Engine

An experimental study of a divided-chamber, stratified-charge engine has been performed using a modified CFR L-head engine. Emissions and fuel consumption were measured over a wide range of overall fuel-air ratio and degree of stratification by varying the prechamber and main chamber inlet fuel-air ratios. High-speed motion pictures of the combustion process and the spatial distribution of fuel-air ratio in the combustion chamber, measured using a sampling valve, were used to explain the trends in the emissions data. Of particular interest is an increase in NO_x emissions with increasing degree of stratification at lean overall fuel-air ratios.