An Experimental Investigation into the GDI Spray Characteristics of Ethanol and Lemon Peel Oil

The fuel injection phenomenon significantly influences engine performance and emissions in a Gasoline Direct Injection (GDI) engine. Before using biofuel in a GDI engine, it is critical to understand its spray structure and combustion quality. The current study seeks to deepen the understanding of the spray behaviour of Lemon Peel Oil (LPO) and ethanol in a controlled environment under different pressure, temperature, and engine-like conditions. The thermophysical properties of the fuels help to comprehend the spray characteristics. The liquid spray morphology of fuels is captured using a standard Mie-scattering technique, and the spray penetration length is compared to the baseline fuel isooctane. The constant volume spray study revealed that the Isooctane has the shortest penetration. The higher boiling point of LPO allows for a longer spray tip penetration. Besides, ethanol has a longer penetration than Isooctane despite its low boiling point. Spray collapsing is observed at 1 bar chamber pressure and 453 K temperature due to flash boiling, which reduced the overall spray cone angle, resulting in greater LPO and ethanol penetration, where Isooctane behaves differently in this chamber condition.