Numerical investigation on cellular detonation reflection over wedges with rounded corner

Numerical investigations were performed to study the reflection of cellular detonation over wedges with rounded corner, and for comparison, reflections over wedges with straight sharp corner were also calculated. Dynamics of the reflection phenomenon were described by the two-dimensional reactive Euler equations based on the platform of OpenFOAM-7, with the utilization of the adaptive mesh refinement (AMR) technology. The reflection process and the influence of the concave section and wedge angle on the reflection were discussed, as well as the transition from Mach reflection to regular reflection. Different kinds of reflection types including the Direct-Mach reflection (DiMR), the Stationary-Mach reflection (StMR) and the Inverse-Mach reflection (InMR) were observed in the concave section. When the detonation initially propagated to the straight section, the influence of the concave section was remembered. Subsequently, the influence was forgotten at a certain point, and the reflection was controlled by the straight section. When the wedge angle was smaller than or equal to 50 degrees, the asymptotic self-similarity approached in the far field, and the asymptotical triple-point angles decreased with the increase of wedge angle. The critical angle for the transition from Mach reflection to regular reflection was 64.17 degrees for concave wedge, which was much larger than that of straight sharp corner wedge (51 +/- 1 degrees).

Automated summary

Numerical investigations were conducted on the reflection of cellular detonation over wedges with rounded corner and compared with reflections over wedges with straight sharp corner. Different types of reflections and the influence of wedge angles were discussed, indicating that the critical angle for transition varied significantly between concave and straight wedges.