Numerical investigation of different configurations for hydrogen fuelled jet engine combustors

The effects of a converging nozzle inside a hydrogen fuelled micromix combustor are presented. The nozzle is placed between the hydrogen injection points and the combustion zone, thus evaluating the effect of partial mixing before combustion takes place. The simulations are performed using the k-ω SST turbulence model and the Eddy-Dissipation Concept. The results show an advantage in steepening the angle of the nozzle in terms of pollutant formation. Furthermore, the results show a sensitivity of the formation of pollutants to the inlet temperature and pressure, which aligns with experimental data available in the literature. The injectors studied lead to an acceptable level of pollutant formation, especially for the 20° test case, which also appears to be more insensitive to inlet conditions variation. Finally, the presence of a converging nozzle appears to be an effective tool for preventing flashback from occurring.