CNG-H2 Engine model in CONVERGE

This thesis follows the study and development of the CFD model of H2 engines using a previous CNG engine model. To do our research, a CFD commercial code CONVERGE was used, which has allowed us to reduce the time for the model pre-processing, thanks to the independent meshing tools its sophisticated algorithms that can refine the mesh locally. All our study was conducted on the Fiat FIRE 1400 16V engine, which is installed in the test bench of DENERG laboratories. In this thesis, the models ECFM and ISSIM were used, which allowed the combustion described by splitting the chemical parameters from the physical one, reducing the numerical cost, and avoiding reproducing all the combustion kinematics. Using 0D and 1D combustion simulator software DARS, the laminar flame speed table was introduced in the converge model. The work can be divided into four main phases: in the first one, we have increased the load in a CNG engine model previously developed and studied in Paolo De Angelis’ thesis. Since experimental data weren’t available for the full load, we used the 0D 1D software GT-POWER to obtain intake and exhaust pressure. Later, we developed a CNG DI engine model in CONVERGE using the SOURCE CELL METHOD and using the previous results in the PFI engine. After this, we have produced a CFD H2 PFI engine using the laminar speed table obtained with DARS. Lastly, we have studied an H2 DI engine model using the CNG engine model previously created and analyzed.