Modeling of Ammonia MILD Combustion in Systems with Internal Recirculation

The present work focuses on the combustion of alternative renewable fuels, ammonia in this case, in a system, such as the Laboratory Unit CYclonic (LUCY) burner. This reactor can operate under Moderate or Intense Low-oxygen Dilution (MILD) combustion conditions thanks to a strong internal recirculation of flue gases. Experimental data, including in-flame temperatures and exhaust gas composition, are available. Numerical simulations based on Computational Fluid Dynamics (CFD) techniques are performed and compared to the experiments to analyze the suitability of existing numerical sub-models. More specifically, a sensitivity analysis is carried out both for the turbulence closure models, i.e., RNG k-& epsilon;, BSL k-& omega; and Reynolds Stress Model, and for the combustion models, i.e. Flamelet Generated Manifold, Eddy Dissipation Concept and Partially Stirred Reactor, incorporating seven different kinetic schemes.