
Investigations on Spark and Corona Ignition of Oxymethylene Ether-1 and Dimethyl Carbonate Blends with Gasoline by High-Speed Evaluation of OH* Chemiluminescence
- Thorsten Langhorst - Karlsruhe Institute of Technology (KIT) ,
- Olaf Toedter - Karlsruhe Institute of Technology (KIT) ,
- Thomas Koch - Karlsruhe Institute of Technology (KIT) ,
- Benjamin Niethammer - Karlsruhe Institute of Technology (KIT) ,
- Ulrich Arnold - Karlsruhe Institute of Technology (KIT) ,
- Jörg Sauer - Karlsruhe Institute of Technology (KIT)
Journal Article
04-11-01-0001
ISSN: 1946-3952, e-ISSN: 1946-3960
Sector:
Topic:
Citation:
Langhorst, T., Toedter, O., Koch, T., Niethammer, B. et al., "Investigations on Spark and Corona Ignition of Oxymethylene Ether-1 and Dimethyl Carbonate Blends with Gasoline by High-Speed Evaluation of OH* Chemiluminescence," SAE Int. J. Fuels Lubr. 11(1):5-20, 2018, https://doi.org/10.4271/04-11-01-0001.
Language:
English
Abstract:
Bio-fuels of the 2nd generation constitute a key approach to tackle both
Greenhouse Gas (GHG) and air quality challenges associated with combustion
emissions of the transport sector. Since these fuels are obtained of residual
materials of the agricultural industry, well-to-tank CO2 emissions
can be significantly lowered by a closed-cycle of formation and absorption of
CO2. Furthermore, studies of bio-fuels have shown reduced
formation of particulate matter on account of the fuels’ high oxygen content
therefore addressing air quality issues. However, due to the high oxygen content
and other physical parameters these fuels are expected to exhibit different
ignition behaviour. Moreover, the question is whether there is a positive
superimposition of the fuels ignition behaviour with the benefits of an
alternative ignition system, such as a corona ignition. To shed light on these
questions two oxygenic compounds, oxymethylene ether-1 (OME1) and dimethyl
carbonate (DMC) have been studied with respect to OH* emission throughout
ignition and onset of flame-front propagation in a combustion chamber with a
large optical access via a quartz window. OH* measurements have been recorded
via a high-speed optical camera (5 kHz) coupled with 308 nm optical filter and
image intensifier. Sealing material swelling tests have yielded a
perfluoroelastomer (FFKM 72) as an ideal, cost-efficient material regardless of
the applied fuel. Comparative measurements with both ignition systems for
combustion of gasoline as well as moderate blend admixtures of OME1 and DMC have
demonstrated the superior ignition stability with likewise implications on
flame-kernel development for the corona ignition. Furthermore a strong influence
of the mode of discharge on OH* formation rates was observed especially for the
oxygenic blends. Finally, for admixture variations of both oxygenates, an
increased OH* level was shown during discharge thereby proving the hypothesis of
a positive superimposition of oxygenic fuel and corona ignition system.