Investigation of the Effect of the Composition of a synthetic Fuel (eFuel) on Combustion Behaviours and Emission

Since years 3D-CFD engine simulation was focused in modelling the engine and its components in order to deeply analyse the in-cylinder events that characterize combustion and emission’s formation. The optimization process that followed the modelling part aimed to modify specific parts of the engine assembly as combustion chamber geometry, piston shape, injector position, injection strategy in order to improve combustion behaviour and pollutants’ emission. This process has always been performed keeping fixed the fuel composition since it was not an adjustable parameter. Nowadays with the introduction of new synthetic fuels (e-Fuels) it is possible to manipulate the related chemical composition, thus this innovation requires also new engine simulation methodologies in order to take into account the effect of the fuel parameter on results in terms of combustion behaviour and emission. Due to the high variety of chemical species inside a fuel, it is mandatory to use a surrogate to represent the real fuel inside the 3D-CFD software environment. The goal of the thesis is to develop a methodology that starting from the chemical composition of the fuel and basic attributes as density and octane rating is able to compute, through the use of artificial intelligence, the surrogate that aims to represent the real fuel inside the 3D-CFD software environment. Results of the simulation will be validated against experimental data in terms of both combustion behaviour and emissions. This methodology opens a new scenario for 3D-CFD engine simulation because it is now possible to take into account the fuel as an adjustable parameter. This means that it is now possible to support the process of creation of new synthetic fuels (e-Fuels) in order to optimize engine performance and related emission. The results of this process can have an impact on the whole car fleet due to the retrofitabilty of e-Fuels, consequently it can be beneficial with an immediate response to the emissions of the transport sector.