Jean-Etienne DURAND
DOI Number: N/A
Conference number: HiSST-2025-048
Beyond the flight Mach number 7, the scramjet, with supersonic combustion, shows higher performances than the ramjet, with subsonic combustion, due to the substantial pressure losses, chemical dissociation effects, and high thermomechanical stresses. The dual-mode scramjet would be a solution to hold optimal performances over an extensive range of flight Mach numbers. The use of a divergent nozzle choked through a thermal throat, generated by heat combustion, turns out to be an elegant approach to switch from subsonic to supersonic combustion processes, avoiding mechanical constraints and complex systems. Furthermore, compared with a conventional ramjet, this approach increases the allowable mass flow rate through the engine, increasing the thrust. However, the strong coupling between the thermal throat and the combustion process could lead to complex, unsteady flow behavior, potentially implying the occurrence of critical phenomena such as flame flashback or inlet unstart [1]. The present work aims to develop an unsteady quasi-1D model of a thermally choked nozzle reacting flow. With this model, the analysis of the unsteady behaviors of the aerothermal flow with a thermal throat becomes accessible, improving the quasi-1D dual-mode scramjet combustor simulation. The finite volume method with the WENO5-HLLC scheme is considered. The responses in
performance and aerothermodynamics of the flow from changes in the inlet global equivalence ratio are studied.