Theory of Mach reflection of detonation at glancing incidence. (6th December 2016)

• Record Type: Journal Article
• Authors: Bdzil, John B.; Short, Mark
• Is Part Of: Journal of fluid mechanics. Volume 811(2017)
• Page Start: 269
• Page End: 314
• Publication Date: 2016-12-06
• Subjects: compressible flows, -- detonation waves, -- high-speed flow; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2016.745
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract : We present a theory for Mach reflection of a detonation undergoing glancing incidence reflection off of a rigid wall. Our focus is on condensed-phase explosives, which we describe with a constant adiabatic gamma equation of state and an irreversible and either state-independent or weakly state-dependent reaction rate. We consider two detonation models: (1) the instantaneous reaction heat-release Chapman–Jouguet (CJ) limit and (2) the spatially resolved reaction heat-release Zeldovich–von Neumann–Dø̈ring (ZND) limit, where here we only consider that a small fraction of the detonation energy release is spatially resolved (the SRHR limit). We observe a three-shock reflection in the CJ limit case, with a Mach shock that is curved. We develop an analytical expression for the triple-point track angle as a function of the angle of incidence. For the SRHR model, we observe a smooth lead shock, akin to von Neumann reflection, with no reflected shock in the reaction zone. Only at larger angles of incidence is a three-shock Mach reflection observed.