Calculated Nitric Oxide Emissions of an Unthrottled Spark Ignited, Stratified Charge Internal Combustion Engine 741171
This paper presents a theoretical study of nitric oxide emissions from an unthrottled stratified charge, spark ignition engine. This investigation was undertaken to determine the nitric oxide production when an ideal rich-lean stratification is present and to determine the effects of introducing an intermediate stoichiometric region. In order to study this problem a three-region (generally rich, stoichiometric, and lean) combustion model was used, and the effects of the following variables were studied:
Excess air number of the rich mixture.
Percentage of the total fuel in the rich-mixture region.
Percentage of fuel burned stoichiometrically.
Exhaust gas recirculation, percentage and distribution.
Comparisons are made to both experimental results from a throttled engine and calculated results for an unthrottled engine with a homogeneous mixture. For illustrative purposes, an application of the model to a particular geometrical form of charge distribution is analyzed.
Citation: Tabaczynski, R. and Klomp, E., "Calculated Nitric Oxide Emissions of an Unthrottled Spark Ignited, Stratified Charge Internal Combustion Engine," SAE Technical Paper 741171, 1974, https://doi.org/10.4271/741171. Download Citation
Rodney J. Tabaczynski, Edward D. Klomp
Research Lab., div., General Motors Corp.
International Stratified Charge Engine Conference