ETD

• Cabra flame
• cfd Large Eddy Simulations
• hydrogen combustion
• sensitivity analysis
• turbulence-chemistry interaction

This thesis presents a parametric numerical investigation with Computational Fluid Dynamics of a hydrogen-fueled lifted diffusion flame, with focus on Turbulence-Chemistry Interaction (TCI). This configuration, known as the Cabra flame, provides a simplified but representative framework of complex physics phenomena, found in applications ranging from commercial boilers to gas turbines. For this reason, it plays a key role as a benchmark for the development and validation of turbulent combustion models.\\
However, simulating the Cabra flame is particularly challenging: the flame lift-off height is conditioned by a balance between auto-ignition and turbulent mixing, which standard Reynolds-Averaged Navier Stokes (RANS) models often fail to capture.\\
Consequently, the present work adopts a Large Eddy Simulation (LES) approach and models the combustion process with the PaSR-LFR framework.\\
A sensitivity study is performed to evaluate the influence of turbulence modeling, mesh resolution and boundary conditions on the predictive accuracy of the simulations.\\
The combustion model employed reproduces the qualitative flame structure but exhibites quantitative discrepancies with experimental data, highlighting critical limitations due to the initial assumptions.\\
Despite these challenges, the study demonstrates the potential of the PaSR-LFR approach within the LES framework, while also pointing out the need for more advanced TCI closures.