Velocity-adjusted Davis products isentrope for program burn calculations

The disparity between the reaction and the engineering length scales in high-explosive (HE) systems motivates the use of program burn methods such as Detonation Shock Dynamics (DSD). DSD replaces the detonation wave with a surface and an evolution equation that precomputes the burn time field based on a curvature-dependent normal detonation velocity. When this velocity differs from the nominal Chapman–Jouguet value (non-zero curvature), the local expansion isentrope of the HE detonation products must be adjusted to yield the correct detonation energy and mathematically consistent post-flow state. We present the derivation of a velocity-adjusted model based on the Davis reference curve. The physical constraints result in a system of nonlinear equations for the free parameters of the equation of state that can be solved numerically. The velocity-adjusted model is evaluated using cylinder test calculations for PBX 9502 at different charge diameters.