Numerical Assessment of the Potential of a Hydrogen Spark Ignition Engine suitable for High Performance Applications

Climate changes and environmental degradation are shaping the future of the transportation sector, opening new horizons to the application of new and innovative technologies. In this scenario, Europe's Green Deal aims to reduce by 90% the greenhouse gas emission in transport by 2050, compared to 1990 levels. In recent years, among different answers to the 2050's target, Battery Electric Vehicles (BEVs) have emerged on the market. However, the interest in hydrogen as a key energy solution for low-emission mobility reawakened recently. It can be employed effectively in Fuel Cells (FCs) and Internal Combustion Engines (ICEs). More in detail, due to its combustion characteristics - rapid mixing and fast flame speed - hydrogen represents a cost-effective and time-saving solution to be implemented in Hydrogen-Fuelled ICE. Additionally, considering the sports cars' niche sector, it can deliver very high performance and efficiency, exploiting more than one century of technological know-how developed with ICEs. In this framework, the task of this document is to convert a state-of- the-art V6 3.0 L gasoline engine into a Hydrogen-Fuelled Spark- Ignition (SI) one - able to deliver the same performance with zero carbon content emission - and conduct a preliminary assessment of its performance and efficiency. For this purpose, a commercial one- dimensional Computational Fluid Dynamic (CFD) software has been used. New methodologies have been conceived to reproduce the different behavior of hydrogen during combustion: a zero-dimensional combustion model that estimates the burn duration of the H2/air mixture as a function of the hydrogen laminar flame speed; a model to evaluate the occurrence of knock during hydrogen combustion; finally, an Engine Control Unit (ECU) in charge of protecting the engine component, ensuring the performance, and avoiding the occurrence of knock. The second part of the work regards the development of a bespoke turbocharger, which has to guarantee high performance despite the lack of energy at the turbine stage due to the exploitation of a lean mixture. Finally, with the best engine concept, transient and steady-state performances - at different loads - have been evaluated.