Supersonic combustion supported by flameholders

The development of hypersonic aspirated propulsion systems, such as scramjet engines, represents a great technological challenge, mainly due to the complex aerothermodynamic processes observed during flight in a sensitive atmosphere. In this context, on-site tests, involving direct and indirect measurements of parameters associated with the exposure of systems and subsystems to hypersonic flight conditions, are an essential step for projects of an innovative nature. In this sense, the present work aimed to evaluate the parameters of supersonic combustion optimization in scramjet models, using flows produced in the T1 Hypersonic Shock Tunnel, installed at the Institute of Advanced Studies, IEAv. This study investigated the flame production, retention and stabilization characteristics in a hydrogen-fed scramjet combustor with backwall expansion cavities at Mach 2.6 inlet condition with stagnation pressure of 3.3 MPa and stagnation temperature of 2100 K. The effects of two flameholder geometries were compared. The experimental results showed that the flameholder with the shortest length and height had the best combustion performance, with a 15% increase in burning efficiency. However, the study of other geometries will be of fundamental importance for the determination of the influence of each parameter in the retention and stabilization of the flame, as well as the optimal configuration of the combustor.