Direct numerical simulation of turbulent premixed ammonia flame: flame structure and heat release characteristics

Given the widespread public interest in carbon neutrality, ammonia represents a potential energy carrier without carbon dioxide emissions. To obtain fundamental insights into the behavior of turbulent premixed lean and rich ammonia flames, high fidelity three-dimensional direct numerical simulations of flames in a channel are performed with complex chemistry. In particular, the heat release characteristics and turbulent flame structure are analyzed. Two cases are considered, for which the unstretched laminar flame speed is matched to provide a physically relevant comparison. The heat release rate analysis reveals that the peak of the conditional mean of heat release rate exceeds the laminar value for lean ammonia flame, but not for the rich ammonia flame. Furthermore, the mean profiles of major species resemble those of the laminar flame for both cases. More detailed analysis and examination of the flame-turbulence interaction and flame propagation characteristics will be provided in the presentation.