Combustion Processes in Model SCRAM Jet Combustor Using Detonation Driven Shock Tunnel

Experiments were conducted in order to investigate mixing and combustion processes in a model SCRAM (Supersonic Combustion RAM) jet combustor equipped with a backward-facing step. A detonation-driven shock tunnel was used to generate high-enthalpy flow of Mach number three. Firstly, an influence of installing a sidewall on the combustor model was investigated. Secondly, flow-fields around the step were visualized using high-speed video camera with an aid of schlieren technique. A hydrogen fuel was injected perpendicular to the supersonic flow behind the backward-facing step and a height of the step and an injection distance were varied in order to investigate the effects of these parameters on a characteristic of the combustion. As a result, the injected hydrogen was ignited behind the step and increasing the height of step became effective to the ignition and flame holding behaviors. Furthermore, a non-dimensional injection distance with respect to height of the step was considered to be an important parameter to influence an ignition and combustion processes in the model SCRAM jet combustor