Effect of Thermal Nonhomogeneity on Explosion or Detonation in an Annular Cookoff

This computational study is motivated by recent experiments on large-scale cookoff in a confined annular geometry, where the explosive charge is heated carefully so as to produce, nominally, a uniform radial thermal gradient. In the absence of circumferential asymmetry a circular wave of explosion would traverse the charge from the hot outer boundary to the cold inner boundary. In practice, however, experimental imperfections induce weak thermal nonhomogeneities during the heating phase, leading to hot spots where ignition may occur preferentially. For a model homogeneous explosive with strongly state-dependent kinetics, this study explores the influence of the nonhomogeneities on the fate of the explosive event.