Evaluation of a new computational fluid dynamics model for internal combustion engines using hydrogen under motoring conditions

The present work conducts a preliminary evaluation of a new CFD (computational fluid dynamics) model, which is under development at the authors' laboratory. Using this model, it is feasible to understand how the intake manifold and in-cylinder geometry affect the in-cylinder flow field and the mixing processes taking place in an Otto (spark-ignition) engine. The model is applied on a high-swirl, two-valve, four-stroke, transparent combustion chamber engine running under motoring conditions. To investigate the fuel–air mixing process, hydrogen is injected in the intake manifold. To evaluate the model three case studies are examined. First, the model is applied to simulate the external mixing in the intake manifold with a tee-mixer injection system. Secondly, the transient gas flow field in the intake manifold and engine cylinder is examined over the complete engine cycle. Finally, the transient mixing process in the intake manifold and the spatial and temporal distribution of species concentrations inside the cylinder are numerically computed using the developed model. To validate the model, the results obtained through the test cases examined are compared either with available experimental data or with simulated results, which are obtained using a commercially available CFD code applied under the same conditions.