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Evaluation of Pre-Chamber Orifice Orientation in an Ethanol-Fueled Spark-Ignition Engine for Passenger Car Applications
Journal Article
03-15-04-0024
ISSN: 1946-3936, e-ISSN: 1946-3944
Sector:
Topic:
Citation:
Burkardt, P., Wouters, C., and Pischinger, S., "Evaluation of Pre-Chamber Orifice Orientation in an Ethanol-Fueled Spark-Ignition Engine for Passenger Car Applications," SAE Int. J. Engines 15(4):471-482, 2022, https://doi.org/10.4271/03-15-04-0024.
Language:
English
Abstract:
The combination of an alternative alcohol-based fuel and a pre-chamber (PC)
combustion process in a spark-ignition (SI) engine allows for both an extension
of the lean limit and an increase of the indicated efficiency, while
simultaneously achieving low engine-out emissions. The orientation of the PC
orifices is crucial for the flow field inside the PC. Orifices with different
swirl angles have already been investigated. However, the influence of the
orifice offset from the PC center with a fixed swirl angle has not been part of
previous research. This study presents investigations of ethanol-fueled
combustion systems on a thermodynamic SI single-cylinder engine (SCE) for
passenger car applications with a compression ratio (CR) of 16.4. Three active
PC layouts with different orifice offsets were investigated. Their combustion
behaviors were compared to that of a conventional SI combustion concept. In
particular, variations of the relative air/fuel ratio (λ) were performed at both
part-load and high-load engine operations. The influence of the different
orifice offsets in terms of both the maximum achievable lean limit and the
indicated efficiency was found to be small since the combustion behavior was
similar for all three PC layouts, and no significant differences in terms of
both the lean limit and the indicated efficiency were observed. Compared to the
SI configuration, the PC configurations achieved higher maximum indicated
efficiencies. At an engine speed of 2000 1/min and an indicated mean effective
pressure (IMEP) of 15 bar, a maximum indicated efficiency of 46.5% was achieved
with a λ of 1.8. Moreover, a maximum λ of 2.0 was achieved with a PC
configuration, while the maximum achievable λ with SI was 1.7. This work
provides insights that help to understand the influence of the PC orifice offset
on the combustion of an active PC application and shows approaches for future
research.