Climate change concerns demand a drastic reduction in CO2 emissions, tending to what is called carbon neutrality. Even if political guidelines promote electrification, considering the transportation sector, not all applications have the same requirements and boundary conditions, and hence, their optimal solution is not necessarily the same. In this context, in parallel with pure electric powertrains, the internal combustion engine (ICE) still has a relevant role to play, mainly in hybrid powertrains, working together with an electrical motor. In this hybridization context, the spark-ignition (SI) engine used to be the most adopted solution because of its lower cost and complexity. Consequently, it can be concluded that the SI engine still has a significant role to play in the near future. However, when ICEs are considered, the search for carbon neutrality requires the use of fuels other than fossil fuels. At this point, many alternatives arise, from biofuels to synthetic e-fuels, or even H2. This extreme variety of fuels introduces complexity from the combustion modeling point of view.
This study proposes a methodology for developing a 0D combustion model that characterizes the engine flame front effective surface area based on a reference fuel (gasoline) and extrapolates it to other engine conditions and/or to other fuels (e.g., H2), predicting the in-cylinder pressure. To allow the prediction for any other fuel, the only requirement is to know the laminar flame speed of that fuel at different operating conditions. The results show that, for different engine conditions, the proposed methodology can predict the in-cylinder pressure with an average error of ~2.1% for reference fuel and an average error of ~2.6% for H2. These findings indicate that the proposed methodology has good performance and could be used for analyses requiring a limited number of experiments and short computational time.