Experimental and numerical investigation of abnormal combustion phenomena in high-performance hydrogen direct-injection engine operated in stochiometric conditions

Nowadays the use of Hydrogen (H2) within Internal Combustion Engine (ICE) represents a valuable solution also for high-performance applications since it allows carbon free combustion process preserving, at the same time, the driving experience of the engines fuelled with conventional fuels. On the other side, the low ignition energy and the high flammability range may lead to a high probability of abnormal combustion events especially at high engine loads. Therefore, this work aims at investigating the occurrence of knock and pre-ignition phenomena in a high-performance Direct Injection (DI) single cylinder Spark Ignition (SI) engine through the synergistic use of numerical simulations and experimental activities. A 3D-CFD model was calibrated against a set of experimental measurements. The engine model showed satisfactory predictive capabilities with a good matching with the experimental in-cylinder pressure traces. This virtual test rig was then used to investigate the impact of a different coolant temperature and different injector recess in terms of knock and pre-ignition tendency, and most of all, to define a robust simulation methodology to estimate the risk of hydrogen abnormal combustion events.