Autoignition Process in Compression Ignition Engine Fueled by Diesel Fuel and Biodiesel with 20% Rapeseed Biofuel in Diesel Fuel

Controlled autoignition delay is considered a very promising new technology, having the potential of combining low fuel consumption with low pollutant emissions. In this study, the effect of pure diesel fuel and biodiesel B20 (20% rapeseed oil mixed with 80% diesel fuel, by volume) on ignition delay period, at different engine speeds, under full load operating conditions, has been investigated experimentally and numerically. For this purpose, two models were proposed. The experimental results were compared with the ignition delay predicted by some correlations and by the considered models. The results showed that the ignition delay period of biodiesel B20 is shorter than that of pure diesel fuel at similar operating conditions. Regarding pure diesel fuel, the ignition delay periods are in good accordance with Arrhenius type correlations, whereas for biodiesel B20 the correlation results are significantly different than the experimental data.