Comprehensive Assessment of Gasoline Spray Robustness for Different Plume Arrangements

Ensuring spray robustness of gasoline direct injection (GDI) is essential to comply with stringent future emission regulations for hybrid and internal combustion engine vehicles. This study presents experimental and numerical assessments of spray for lateral-mounted GDI sprays with two different plume arrangements to analyze spray collapse characteristics, which can significantly deteriorate the atomization performance of fuel sprays. Novel spray characterization methods are applied to analyze complex spray collapse behaviors using diffusive back-illuminated extinction imaging (DBIEI) and 3D computed tomographic (CT) image reconstruction. A series of computational fluid dynamics (CFD) simulations are performed to analyze the detailed spray characteristics besides experimental characterization. Spatio-temporal plume dynamics of conventional triangle-pattern spray are evaluated and compared to a plume pattern with an inversed T pattern that has more open space between plumes. The results show that the triangular pattern, with plumes enclosed by other plumes, indicated significant spray collapse behavior under various conditions. The inversed-T pattern, the opened pattern where plumes are arranged not to have a closed volume, had better robustness against collapse due to an open layout, which prevents an imbalance of the local pressure field that may cause collapse. The approach applied in this study to mitigate spray collapse was verified to be effective and can be referenced in spray design to ensure the robustness of GDI sprays.