Structure and propagation characteristics of turbulent premixed NH₃-H₂O₂ flame

In this work, three-dimensional direct numerical simulations of lean turbulent premixed flames are conducted using a recently developed skeletal reaction mechanism to investigate the distinctive characteristics of NH₃-H₂O₂-air mixtures with up to 20% H₂O₂ in the fuel blend. The analysis of the turbulent flame speed and flame structure shows that the addition of hydrogen peroxide to ammonia leads to two peaks in the heat release rate profile and broadens the reaction zone. Despite this change in the flame structure, the ratio of turbulent flame speed to laminar flame speed remains comparable to that of a lean ammonia-air flame. The study further delves into data-driven interpretation of a DNS dataset, concentrating on the80%NH₃-20%H₂O₂-air flame. Applying VQPCA clustering on temperature and mass fractions underscores the significance of radicals such as HO₂, N₂H₄, H₂NN, H₂NO, and HNOH in the generation of the early heat release rate peak.