• idrogeno
• CFD

The aim of this thesis is to simulate the hydrogen direct injection and mixing into the suitably modified four stroke Lombardini Diesel engine 15 LD 500, through a thermo-fluid dynamic code and to compare the results with experimental data previously obtained at the brake. The model had to verify the influence of many parameters on the mixing, such as the start of injection, the mutual inclination of injectors, the injection pressure and the geometry of the combustion chamber. The 3D model of the original engine, which was already modeled for other theses, was used and, with CoCreate Modeling 2008 CAD, was modified in order to turn it from Diesel into hydrogen. The modified geometry was exported to Gambit 2.3.16, in order to create the mesh. The obtained mesh was then exported to Fluent 13 which computed the solutions by the imposition of boundary conditions, initial conditions, mesh updating parameters and solution methods definition. Although the complexity of the system, the lack of some parameters (such as the actual internal geometry of injectors or wall temperature, which are a function of combustion temperature and therefore of local mixing) the obtained results can be considered in agreement with the experimental data, validating the usefulness of CFD as top operation for studying and designing all thermo-fluid dynamic systems.