  I report on a novel simple reactive-flow model that captures corner-turning
behaviour, including failure and the creation of dead zones, in insensitive
solid heterogeneous high explosives. The model is fast, has a minimum of free
parameters, and is physically grounded in the underlying initiation and burn
phenomena. The focus of the model is explosives based on
triaminotrinitrobenzene (TATB), although the model is quite general. I
initially developed the model and integrated it into a branch of a Lawrence
Livermore National Laboratory (LLNL) arbitrary Lagrangian-Eulerian (ALE) code
concurrently with other modelling efforts of mine, but I subsequently adopted
it to study corner-turning behavior in the TATB-based high explosive PBX 9502
when two other available models suggested to me proved inadequate, being either
prohibitively computationally expensive or numerically unstable. An early
version of the model reproduces corner-turning behavior in two different
double-cylinder tests and a mushroom-type corner turning test. The model was
informed and influenced by other reactive-flow models applicable to shock
initiation or corner-turning, most especially including JWL++ Tarantula 2011
and an in-house piecewise-linear CHEETAH-based model that exhibits
corner-turning behaviour, but also, to a degree, by Ignition & Growth (I&G),
CREST, and the Statistical Hot-Spot Model. The model also shares some
similarities to SURF models. In this paper, I describe the model and its
theoretical development as I originally conceived it, as well as subsequent
improvements.
