Comparative Study of Diesel Oil and Biodiesel Spray Combustion Based on Detailed Chemical Mechanisms

Abstract

In the present work, a semidetailed combustion mechanism for biodiesel fuel was validated against the measured autoignition delay times and subsequently implemented in the fortأ‰ cfd engine simulation package (Reaction Design Inc., 2010, “fortأ‰, FORUG401021009UG1b,â€‌ Reaction Design Inc., San Diego, CA) to investigate the spray characteristics (e.g., the liquid penetration and flame liftoff distances of rapeseed oil methyl ester (RME) fuel in a constantvolume combustion chamber). The modeling results were compared with the experimental data. Engine simulations were performed for a Volvo D12C heavyduty diesel engine fueled by RME on a 72 deg sector mesh. Predictions were validated against measured incylinder parameters and exhaust emission concentrations. The semidetailed mechanism was shown to be an efficient and accurate representation of actual biodiesel combustion phases. Meanwhile, as a comparative study, the simulations based on a detailed diesel oil surrogate mechanism were performed for diesel oil under the same conditions.