Numerical Investigation of a Detonation Wave System in a Scramjet Combustor

摘要

Detonation wave system in a hydrogen fueled scramjet combustor with a hyper-mixer injector is investigated by unsteady 3D-CFD (RANS) for a Mach 8 flight enthalpy condition. The main purposes of the present investigation are to reveal 1) the processes of formation, upstream propagation and decay of the detonation wave system, which were observed in a combustion experiment at the High Enthalpy Shock Tunnel (HIEST) of JAXA, 2) the structures of the detonation wave system and their changes during the upstream propagation process depending on the equivalence ratio, and 3) mixing and combustion flowfields affected by the detonation wave propagation, especially the process of flame propagation and flameholding. The numerical simulation successfully reproduced the series of detonation wave processes, i.e. detonation wave formation, upstream propagation, decay from normal shock to oblique shock structures, and final quasi-steady combustion flowfield. Dependencies of the detonation wave processes and wave structures on the equivalence ratios, 0.45 and 1.0, were also revealed. In this paper, we will present these phenomena in detail together with other key results of the numerical simulation.