CFD study on a Stirling burner based on MILD combustion and diluted mixtures

The work presented in this paper presents comparison of results from the experimental facility in Chalmers University of Technology and 3D CFD combustion simulations based on both RANS and hybrid URANS/LES (SAS-SST model) turbulence models applied to the GasBox combustion chamber at atmospheric pressure. The combustion is modelled using the Eddy Dissipation Model coupled with Finite Rate Chemistry using different optimized global reaction mechanisms. The gas composition has been varied from pure methane gas to low energy content, such as landfill gas mixture consisting of 26.8% CH4, 32.2% CO2, 2.0% O2 and 39.0% N2 by volume. There is a good agreement between the quantities predicted with hybrid URANS/LES and the experimental data, in terms of flow and flame dynamics, averaged temperatures and the concentrations of some major species.