Large-Eddy Simulation of a Supersonic Burner

Large eddy simulations of a supersonic hydrogen-air burner have been performed with the SiTComB numerical code. A reduced kinetic scheme is used and chemical source terms are evaluated based on resolved quantities. Three mesh resolutions have been considered: 2, 30 and 113 million of points (MP). With 2MP the flame is unstable and no comparison with experimental data becomes possible. However, the flame lift-off height is over predicted for the case 30MP. Refining the mesh (113MP) improves the capture of mixing and the flame lift-off height gets close to the experimental results. However this case must be be further converged to get accurate and final conclusions. Scatterplots of temperature and species mass fractions follows the trends already observed in past studies. A lookup table of auto-ignition is built for different levels of pressure and composition corresponding to the values found in the large-eddy simulation. Delays of auto-ignition are found of the order of magnitude of the time required to convect a pocket of pure fuel at a constant speed equal to the fuel inlet velocity.