Experimental Investigation on Spray Characteristics of Polymethoxy Dimethyl Ether as a Sustainable Fuel Applied to Diesel Engine

As global efforts to combat climate change and promote sustainable development intensify, PODEn, as an innovative type of clean, sustainable fuel, has gained growing attention for its potential to support eco-friendly energy transitions, especially concerning the spray characteristics of its blended fuels. Environmental conditions are crucial in the fuel spraying process, which is essential for optimizing combustion efficiency and reducing emissions—key elements of sustainable energy use and climate action. In this study, the parameters of spray morphology, droplet size distribution, and velocity were accurately measured using a constant-volume combustor and high-speed photography. The results demonstrate that as ambient pressure increases, both the spray cone angle and boundary gas entrainment volume increase, while the spray penetration distance and spray volume decrease. These changes, driven by pressure differences and variations in gas density that influence droplet movement and fragmentation, are critical for optimizing fuel injection strategies to enhance combustion efficiency and reduce environmental impact. This aligns closely with the Sustainable Development Goals focused on clean energy, responsible consumption, and climate mitigation. Conversely, as ambient temperature rises, the penetration distance and spray volume increase, whereas the entrainment volume decreases and the spray cone angle narrows. This phenomenon results from the combined effects of temperature on gas density, viscosity, evaporation rate, and convective flow, underscoring the need for adaptive engine designs that leverage these characteristics to improve fuel efficiency and reduce carbon emissions—an essential step toward sustainable development in the energy and automotive sectors.