An analytical study for detonation wave boundary layer interactions under reflections

Numerical simulations and theoretical models are developed in this paper for the Detonation-Wave/Boundary-Layer Interactions (DWBLIs) under reflections. Transient flow fields demonstrate the highly non-stationarity of the DWBLIs when Mach Reflection (MR) occur, and subsequent analyses show that the subsonic region introduced by the boundary layer exacerbates the instability. Further quantitative analyses show that viscosity has little effect on propulsive performance and the separation wave can be considered as an oblique detonation wave. Influence parameters to DWBLIs such as combustion chamber height, incoming Mach number, equivalence ratio, and inlet channel length are categorized and studied. Besides simulations, theoretical analytical modeling is established for Regular Reflection (RR) and MR of DWBLIs. Multiple formulas for the separation zone length are obtained according to the mass conservation under different transformation type between inviscid and viscid reflections. Comparison with the numerical simulations verifies the validity of the model and it can be further generalized to the curved DWBLIs. The developed model makes the theoretical solution process of DWBLIs possible and provides the key foundation for further analysis and solution.