LES of turbulent reacting flow in a rocket based combined cycle combustor

Large Eddy Simulation (LES) has been used to examine the turbulent reacting flow in a model Rocket Based Combined Cycle (RBCC) combustor with a focus on the underlying flow-mixing-combustion physics in the combustor with supersonic fuel-rich rocket jet. For the purpose of validation for the numerical methods and combustion mechanisms, a laboratory scramjet is used as the test-computational configuration. The LES results are compared with shadow-pictures and measurements of velocity and temperature at different cross-sections. In addition, a simplified RBCC combustor is designed with a strut rocket in the middle of the flow path. LES of the hydrogen-fueled RBCC combustor is carried out to investigate the nature of mixing and combustion of the rocket’s supersonic exhaust flow and the air stream. The interaction of the rocket jet and the air flow are studied with a particular focus on the supersonic shear layer that forms at the interface between them. Flow features are examined and a particular emphasis is placed upon the role of the strut rocket in the high-speed reacting flow since its fuel-rich hot gas acts as the ignition source and pilot flame, which is conducive to efficient combustion in the engine.