Effects of External EGR Loop on Cycle-to-Cycle Dynamics of Dilute SI Combustion

Event
SAE 2014 World Congress & Exhibition
Authors Abstract
Content
Operation of spark-ignition (SI) engines with high levels of charge dilution through exhaust gas recirculation (EGR) achieves significant efficiency gains while maintaining stoichiometric operation for compatibility with three-way catalysts. Dilution levels, however, are limited by cyclic variability-including significant numbers of misfires-that becomes significant with increasing dilution. This variability has been shown to have both stochastic and deterministic components. Stochastic effects include turbulence, mixing variations, and the like, while the deterministic effect is primarily due to the nonlinear dependence of flame propagation rates and ignition characteristics on the charge composition, which is influenced by the composition of residual gases from prior cycles.
The dynamics of operation with an external EGR loop differ substantially from those of dilute operation without external recirculation, both in time-scale and cylinder-synchronization effects, especially when misfires are encountered. This paper examines these differences and the implications for prior-cycle-based control strategies.
Meta TagsDetails
DOI
https://doi.org/10.4271/2014-01-1236
Pages
9
Citation
Kaul, B., Finney, C., Wagner, R., and Edwards, M., "Effects of External EGR Loop on Cycle-to-Cycle Dynamics of Dilute SI Combustion," Engines 7(2):606-614, 2014, https://doi.org/10.4271/2014-01-1236.
Additional Details
Publisher
Published
Apr 1, 2014
Product Code
2014-01-1236
Content Type
Journal Article
Language
English