(230e) Ignition of Energetic Material Using a Subscale Frank-Kamenetskii Model with Detailed Chemical Kinetics

Petsev, N. D. - Presenter, Los Alamos National Lab
Ma, X., Los Alamos National Laboratory
Henson, B., Los Alamos National Laboratory
Clements, B., Los Alamos National Laboratory
We present a subscale model for conductive burning in an explosive material featuring a complex kinetic network. Our approach is based on the Frank-Kamenetskii thermal ignition model, with numerical solutions obtained using the method of weighted residuals, as originally proposed by Bennet et al. [J. Mech. Phys. Solids, 46, 2303, 1998]. The subscale model incorporates localized heating of the solid energetic material due to grain-scale phenomena like frictional heating of small cracks, resulting in ignition. This framework, coupled to a physically-based kinetic model for the reaction, is applied to the problem of conductive burning of octahydro-1,3,5,7-tetranitro-1,3,4,7-tetrazocine. Two distinct burning regimes are observed: 1) a “fast burn” mode with millisecond time-to-ignition, and 2) a “slow burn” mode where the material ignites orders of magnitude more slowly. We present data delineating between these regimes, including propagation velocities for the reaction front under varying conditions, and discuss future extensions and applications of this model.