Numerical investigation on cellular detonation reflection over wedges with rounded corner

• Published in: Acta astronautica 2021-04, Vol.181, p.503-515
• Main Authors: Li, Jianxing, Pan, Jianfeng, Jiang, Chao, Zhu, Yuejin, Zhang, Yi, Oluwaleke OJO, Abiodun
• Format: Article
• Language: English
• Subjects: Angle of reflection; Asymptotic properties; Cellular detonation; Critical angle; Detonation; Euler-Lagrange equation; Grid refinement (mathematics); Mach reflection; OpenFOAM; Regular reflection; Rounded corner wedge; Self-similarity
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2021.01.053

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°, 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° for concave wedge, which was much larger than that of straight sharp corner wedge (51 ± 1°). •Simulation were taken on the platform of OpenFOAM using AMR technology.•Different kinds of Mach reflections were observed in the concave section.•Influence of the concave section was limited but should not be ignored.•Asymptotical triple-point angles decreased with the increase of the wedge angle.•Critical angle for rounded corner wedge was larger than that of straight wedge.