Understanding and Qualifying Hydrogen Combustion Related Phenomena for Low-Carbon Mobility

The reduction of the overall greenhouse gas and pollutant emissions from ground vehicles is mandatory to fight against global warming and health issues. Moreover, regarding the increasing demand related to the population growth, the energy requirement for mobility may significantly increase during coming years. Meeting greenhouse gas emission targets is not only about commitment to regulations but also fundamentally about enhancing human well-being. Consequently, the diversification of low-carbon energy sources is of huge interest.The use of Hydrogen (H2) as a sustainable energy source in ground transportation is an alternative or a complementary solution to the full electric vehicles. Hydrogen for mobility can be used in two types of energy converters: The Proton-Exchange Membrane Fuel Cell or the H2 adapted Internal Combustion Engine (H2-ICE). This last has the advantage of its strong maturity with the reuse of existing production infrastructures from conventional ICE and low raw material cost. Nevertheless, the specificities of the hydrogen require some evolutions of the ICE and further understandings and qualifications for its optimization.This study aims to dissect the various phenomena occurring in the combustion system of a Hydrogen ICE. Indeed, it is proposed to consider each phenomenon separately, using both experimental and numerical approaches. The experiments are performed in a canonical tabletop setup (High Pressure/High Temperature vessel) with several optical accesses allowing the use of advanced optical diagnostics such as Schlieren and Laser Induced Fluorescence. This setup was modified to mimic the conditions encountered in the H2-ICE. The experimental measurement is combined with 3D-CFD to investigate the details from the mixing to the combustion. This study brings valuable information on the different phenomena and allows to identify some key levers for the optimization of Hydrogen ICEs.Indeed, the use of such an experimental setup compared to traditional Internal Combustion Engine experiments offers the significant advantage of enabling controlled conditions and the use of advanced measurement devices. This approach provides precise insights and detailed descriptions of the phenomena under operating conditions that closely mimic those found in engines, thereby contributing to a deeper understanding and optimization of hydrogen combustion mechanisms.In addition, the experimental work plays a crucial role in calibrating and validating the advanced 3D CFD computational tool. This validated tool can subsequently be employed to support the development of hydrogen engines by providing reliable and detailed simulations of hydrogen combustion processes under a wide range of operating conditions. This synergy between experimental and numerical approaches ensures a robust framework for optimizing hydrogen engine performance and sustainability.