Generalized Supersonic Flow Characteristics for 2D Rotational, Non-Isentropic Flow with Application to Influence of Confinement on Detonation Propagation

Detonations are supersonic waves consisting of a lead shock driven by energy release from reacting flow. In high explosives, the structure of the reaction zone is strongly influenced by the effects of surrounding (strong or weak) confinement. The high detonation pressures (tens of GPa) generated causes the material confinement to deflect, inducing a multi-D structure to the detonation reaction zone and thereby influencing both the rate of propagation and confinement push. Structurally, a multi-D sonic plane in the frame of the detonation shock separates regions of subsonic and supersonic flow and defines the boundary of influence that can affect detonation propagation. However, we have recently discovered that information flow from the confinement boundaries is able to propagate through the supersonic flow region and impact the sonic boundary, thus influencing the detonation driving zone structure. In order to analyze this information flow, we have constructed a 2D characteristic flow analysis that applies generally to rotational, non-isentropic flow. We apply this construction to analyze the influence of confinement boundaries on detonation propagation in 2D planar and circular arc geometries.