Fuel effects on flame lift-off under diesel conditions
Abstract
An apparent relation between the lift-off length under diesel conditions and the ignition quality of a fuel has previously been reported. To cast light on the underlying mechanism, the current study aims to separate flame lift-off effects of the chemical ignition delay from those of other fuel properties under diesel conditions. Flame lift-off was measured in an optical diesel engine by high-speed video imaging of OH-chemiluminescence. Fuel and ambient-gas properties were varied during the experiment. Only a weak correlation was found between ignition delay and lift-off length. The data indicate that this correlation is due to a common, stronger correlation with the ambient oxygen concentration. The chemical ignition delay and the fuel type had similar, weak effects on the lift-off length. A recently proposed mechanism for lift-off stabilization was used to interpret the results. It assumes that reactants approaching the lift-off position of the jet are mixed with high-temperature products found along the edges of the flame, which trigger autoignition. In this picture, the fuel effect is most likely due to differences in the amount of mixing with high-temperature products that is required for autoignition. In the current experiment, all lift-off effects seem to arise from variations in the reactantmore »
- Authors:
-
- Lund University (Sweden). Dept. of Energy Sciences
- Publication Date:
- OSTI Identifier:
- 21396161
- Resource Type:
- Journal Article
- Journal Name:
- Combustion and Flame
- Additional Journal Information:
- Journal Volume: 158; Journal Issue: 1; Other Information: Elsevier Ltd. All rights reserved; Journal ID: ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 33 ADVANCED PROPULSION SYSTEMS; AUTOIGNITION; LENGTH; FUELS; TEMPERATURE RANGE 0273-0400 K; DIESEL ENGINES; FLAMES; CHEMILUMINESCENCE; COMBUSTION KINETICS; CORRELATIONS; OXYGEN; ANTIKNOCK RATINGS; IGNITION QUALITY; JETS; MIXING; STABILIZATION; VARIATIONS; TIME DELAY; Diesel combustion; Lift-off length; Ignition enhancers
Citation Formats
Persson, Helena, Andersson, Oeivind, and Egnell, Rolf. Fuel effects on flame lift-off under diesel conditions. United States: N. p., 2011.
Web. doi:10.1016/J.COMBUSTFLAME.2010.07.020.
Persson, Helena, Andersson, Oeivind, & Egnell, Rolf. Fuel effects on flame lift-off under diesel conditions. United States. https://doi.org/10.1016/J.COMBUSTFLAME.2010.07.020
Persson, Helena, Andersson, Oeivind, and Egnell, Rolf. 2011.
"Fuel effects on flame lift-off under diesel conditions". United States. https://doi.org/10.1016/J.COMBUSTFLAME.2010.07.020.
@article{osti_21396161,
title = {Fuel effects on flame lift-off under diesel conditions},
author = {Persson, Helena and Andersson, Oeivind and Egnell, Rolf},
abstractNote = {An apparent relation between the lift-off length under diesel conditions and the ignition quality of a fuel has previously been reported. To cast light on the underlying mechanism, the current study aims to separate flame lift-off effects of the chemical ignition delay from those of other fuel properties under diesel conditions. Flame lift-off was measured in an optical diesel engine by high-speed video imaging of OH-chemiluminescence. Fuel and ambient-gas properties were varied during the experiment. Only a weak correlation was found between ignition delay and lift-off length. The data indicate that this correlation is due to a common, stronger correlation with the ambient oxygen concentration. The chemical ignition delay and the fuel type had similar, weak effects on the lift-off length. A recently proposed mechanism for lift-off stabilization was used to interpret the results. It assumes that reactants approaching the lift-off position of the jet are mixed with high-temperature products found along the edges of the flame, which trigger autoignition. In this picture, the fuel effect is most likely due to differences in the amount of mixing with high-temperature products that is required for autoignition. In the current experiment, all lift-off effects seem to arise from variations in the reactant and product temperatures, induced by fuel and ambient properties. (author)},
doi = {10.1016/J.COMBUSTFLAME.2010.07.020},
url = {https://www.osti.gov/biblio/21396161},
journal = {Combustion and Flame},
issn = {0010-2180},
number = 1,
volume = 158,
place = {United States},
year = {Sat Jan 15 00:00:00 EST 2011},
month = {Sat Jan 15 00:00:00 EST 2011}
}