Numerical study on detonation reflections over concave and convex double wedges

Abstract

The solver DCRFoam is used to analyze the characteristics of detonation reflection over concave and convex double wedges. Seven reflection processes are observed depending on the wedge angles (θ1 and θ2), the critical angle of a single surface (θc,single), and the angle difference (Δθ). For concave wedges with small θ1 and Δθ, a Mach reflection is established along the first surface and the leading edge of the second surface. At the end of the second surface, either a Mach reflection or a regular reflection could be observed depending on the θ2. For concave wedges with large θ1 and Δθ, the Mach stem formed over the first surface regularly reflects at the leading edge of the second surface. Then the incident wave regularly reflects over the tail of the second surface. For concave wedges, the actual critical angle of the second surface is found to be larger than the θc,single. While the second surfaces of convex double wedges are found to have the same as a single surface. The detonation reflection processes over convex wedges are much simpler.