Computational realization of turbulent combustion in a scramjet combustor stabilized by a lobed strut

Currently, there are theoretical and technical challenges to organize stable flame in scramjet, especially for variable flight conditions. This paper applies the numerical simulation to investigate and analyze the combustion characteristics in a lobed strut-stabilized scramjet combustor under different conditions of Mach number ( Ma ). By comparing with the experiment date of hydrogen mole fraction, the reliability of large eddy simulation solver used in this paper is verified. On this basis, the simulations of mixing and combustion cases at Ma 1.5–3.0 are carried out separately. The numerical results show the streamwise vortices induced by the lobed strut enhance the mixing and are conducive to the subsequent stable combustion. The turbulent flame behaves lifted characteristics, and the auto-ignition provides the initial active radicals for its stabilization. There are two chemical reaction modes in the flow field, namely auto-ignition, and flame. Further comparison of the cases of different Mach numbers indicates that the lifted height of the flame depends on the Mach number. Analysis of probability density function (PDF) reveals that Mach number influent the competitive relationship between the auto-ignition mode and the flame mode. The auto-ignition and the flame coexist downstream in high ma cases, while the flame mode is the dominant in low Ma cases. • A high-precision LES is performed in a scramjet combustor stabilized by a lobed strut. • The auto-ignition provides the initial active radicals for the stable lifted flame. • The Mach number influents the relationship between the auto-ignition and the flame.