The assessment of autoignition of modified jet fuels

Abstract

The condition of the natural environment, including breathable air, indicates that actions are to be taken related to the reduction of exhaust emissions from transport. One of the sectors of transport is aviation. The reduction of emissions is tightly related to the types of fuels in this sector of transport. In the paper, the authors propose the application of a new generation of jet fuels. A full exploration of the physicochemical properties of these fuels requires research under actual engine operation. The conducted research pertains to the autoignition of modified jet fuels in terms of the thermodynamic indicators and optical analyses of the early phase of flame development. The investigations were conducted using a Rapid Compression Expansion Machine with a simultaneous recording of images using a high-speed camera. Owing to this technique, the authors could assess the thermodynamic properties and analyze the early flame development processes. The investigations enabled the assessment of fuel properties indicating an increased delay of the autoignition process compared to the reference fuel (diesel fuel). The performed analyses have confirmed a huge role of modern fuels (including HEFA in particular) in contemporary aviation–significant delay of autoignition at a simultaneous significant formation of autoignition spots and high intensification of combustion.