Based on experiments conducted on an inline three-cylinder
Atkinson cycle gasoline engine designed for hybrid applications, the CFD model
of in-cylinder combustion under dual injection was
developed for a common hybrid engine according to the operating conditions of 2
000 r/min and 0.6 MPa. The model was further validated for accuracy. Then the
ignition timing sweep simulations were carried out under conditions of no EGR
and 7% EGR rate to investigate the comprehensive effects of varying EGR rates
on combustion and emissions in the Atkinson cycle engine. The results showed
that the introduction of EGR increased the average tumble ratio by 0.05, reduced the turbulent kinetic energy
during combustion, extended the ignition delay period by an average of 5° and prolonged the combustion duration by an average of 10°. Furthermore, EGR reduced NOx emissions by over 80%, but doubled the increase of CO emissions. Ignition timing had little
effect on the tumble ratio and turbulent kinetic energy. Under the 7% EGR
condition, increasing the ignition advance angle led to a smaller increase in
NOx and a more significant
reduction in CO emissions.
SHU Jun, HE Siyue, HUANG Jianxiang
. Effects of EGR and Ignition Timing on In-Cylinder Combustion Process of Atkinson Cycle
Engine[J]. Vehicle Engine, 2025
, 0(6)
: 22
-28
.
DOI: 10.3969/j.issn.1001-2222.2025.06.004
