SOME FEATURES OF THE CURVATURE OF A 2-DIMENSIONAL DETONATION SHOCK FRONT AT A SIMPLE REFRACTION LOCUS

We present a theoretical study of the interaction of a constant-veloci ty two-dimensional detonation wave with its surrounding medium. For th e case of pure refraction, we obtain exact expressions for the interfa ce curvatures of the shock fronts in both the explosive (X) and its co nfinement (C) in terms of the detonation velocity D, the material prop erties of X and C and, if the flow is cylindrically symmetric, the rad ius of the explosive charge. These relations are obtained from the con straints imposed on the flow derivatives of the pressure P and the flo w turning angle theta by the conservation laws, the boundary condition s at the curved shock fronts and the contact conditions matching P and theta along the interface. This model is used in our numerical analys is of a polytropic explosive with a pressure-dependent decomposition r ate and a polytropic confinement. We find that, for a given D, the exp losive's interface curvature C-x decreases as the confinement's densit y increases.