Experimental Investigation of Injection Pressure Fluctuations Employing Alternative Fuels 2020-01-2122

Injection pressure oscillations are proven to determine considerable deviations from the expected mass flow rate, leading to the jet velocities non-uniformity, which in turn implies the uneven spatial distribution of A/F ratio. Furthermore, once the injector is triggered, these oscillations might lead the rail pressure to experience a decreasing stage, to the detriment of spray penetration length, radial propagation and jet break-up timing. This has urged the research community to develop models predicting injection-induced pressure fluctuations within the rail. Additionally, several devices have been designed to minimize and eliminate such fluctuations. However, despite the wide literature dealing with the injection-induced pressure oscillations, many aspects remain still unclear. Moreover, the compulsory compliance with environmental regulations has shifted focus onto alternative fuels, which represent a promising pathway for sustainable vehicle mobility. This scenario has motivated the authors to undertake an experimental campaign devoted to assess the rail pressure fluctuations employing neat diesel and two furan-based blends under various injection settings. The blends are referred as MF30 and MF50, given the volumetric composition of 30% and 50% of 2-methylfuran, respectively. The paper describes the technical and scientific details of the research activity, which aims to provide a further insight into the correlation of rail pressure fluctuations with fuel properties.