Development and validation of a 1D-CFD combustion and emission model for a diesel hydrogen dual fuel marine medium-speed engine

Hydrogen utilization in internal combustion engines represents a promising pathway due to its negligible carbon content. Within this framework, this work presents novel combustion and emissions models for a diesel hydrogen dual fuel engine, enabling efficient system level analysis. A compression ignition engine retrofitted from conventional diesel operation was selected as a test case and modified with a port fuel injection system to supply gaseous hydrogen. The combustion model is based on an ignition delay metamodel derived from detailed chemical kinetics, capturing both the promoting and inhibiting effects of hydrogen on diesel ignition. Additionally, the spray penetration model was modified, improving agreement with experimental data across all investigated conditions. The model was validated against an extensive experimental campaign, achieving low RMSE values for MFB50 and burn duration (1.20 deg and 1.61 deg, respectively). Finally, a NOx emissions sub-model was integrated, confirming the accuracy and robustness of the proposed simulation framework.