Investigation of the ignition and combustion processes of a dual-fuel spray under diesel-like conditions using computational fluid dynamics (CFD) modeling

Abstract

Recent research activities in the field of diesel engines have shown the potential to reduce pollutant emissions and improve the thermal efficiency by controlling the fuel reactivity. However, understanding the impact of blending fuels with different physical and especially chemical properties on diesel-like spray mixing and combustion processes is still a challenge. Since the experimental techniques are still far from providing detailed temporal and spatial information about local spray conditions, computational fluid dynamics (CFD) modeling tools have become the key source of information for investigating the characteristics of these dual-fuel sprays. In this frame, the present research focuses on modeling a dual-fuel spray in diesel-like conditions, comparing different gasoline and diesel blends in terms of ignition characteristics and flame structure. The results confirm the suitability of the state of the art computational CFD modeling tools for reproducing the complex phenomena associated to dual-fuel sprays. Moreover, the important benefits provided by dual-fuel blends, considering the expected reduction in pollutant emissions as a consequence of the differences observed in terms of flame structure, are confirmed.