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Isobaric Combustion for High Efficiency in an Optical Diesel Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on April 14, 2020 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Isobaric combustion has been proven a promising strategy for high efficiency as well as low nitrogen oxides emissions, particularly in heavy-duty Diesel engines. Previous single-cylinder research engine experiments have, however, shown high soot levels when operating isobaric combustion. The combustion itself and the emissions formation with this combustion mode are not well understood due to the complexity of multiple injections strategy. Therefore, experiments with an equivalent heavy-duty Diesel optical engine were performed in this study. Three different cases were compared, an isochoric heat release case and two isobaric heat release cases. One of the isobaric cases was boosted to reach the maximum in-cylinder pressure of the isochoric one. The second isobaric case kept the same boost levels as the isochoric case. Results showed that in the isobaric cases, liquid fuel was injected into burning gases. This resulted in shorter ignition delays and thus a poor mixing level. The lack of fuel/air mixing was clearly the main contributor to the high soot emissions observed in isobaric combustion. The lower heat losses of the isobaric strategy were further explained by tracking the chemiluminescence. Unlike a long single injection, multiple injections helped to contain the hot gases away from the walls. However, the opposite effects were also found from the high thermal radiation caused by the extensive soot formation. High-pressure fluctuations from the rapid heat release of the isochoric case were further seen. Finally, better mixing for improved air utilization was deemed needed when utilizing isobaric heat release.
- Gustav Nyrenstedt - King Abdullah University of Science & Technology
- Abdullah Al Ramadan - King Abdullah University of Science & Technology
- Qinglong Tang - King Abdullah University of Science & Technology
- Jihad Badra - Saudi Aramco
- Emre Cenker - Saudi Aramco
- Moez Ben Houidi - King Abdullah University of Science & Technology
- Bengt Johansson - King Abdullah University of Science & Technology
CitationNyrenstedt, G., Al Ramadan, A., Tang, Q., Badra, J. et al., "Isobaric Combustion for High Efficiency in an Optical Diesel Engine," SAE Technical Paper 2020-01-0301, 2020.
Data Sets - Support Documents
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