Corner Turning with the Ignition & Growth Model A.K. Kapila and D.W. Schwendeman, RPI

1. Corner Turning with the Ignition & Growth Model A.K. Kapila and D.W. Schwendeman, RPI Progress (left) and pressure (right) 2d, 90 degree corner 2d, 140 degree corner Axisymmetric, “hockey-puck” experiment geometry • Highlights: • Well-resolved numerical simulations (with AMR) of detonation diffraction around a corner for various 2d and axisymmetric geometries. • Two sets of reaction rate parameters modeling LX-17 and PBX-9502 (based on previously published data). • Early behavior shows a decoupling of shock from reaction zone locally near the corner for all cases considered. • Detonation re-forms at later times due to lateral pressure effects, and this behavior appears to be a robust feature of the ignition & growth model.

2. Two-dimensional, 90 degree corner Progress Pressure Leading shock separates from the reaction zone at early times. Reaction strengthens down-wards and laterally behind the shock. Reaction zone ultimately reconnects with the shock at later times. A.K. Kapila and D.W. Schwendeman Rensselaer Polytechnic Institute

3. Two-dimensional, 140 degree corner Progress Pressure Leading shock separates from the reaction zone, reaction products roll up near corner. Reaction strengthens down-wards and laterally behind the shock. Re-established detonation reflects from rigid boundary. A.K. Kapila and D.W. Schwendeman Rensselaer Polytechnic Institute

4. Axisymmetric “hockey-puck” experiment geometry axis of symmetry Progress axis of symmetry Pressure The now spherical leading shock separates from the reaction zone near the corner. Lateral compression strengthens the reaction behind the shock. Re-established detonation reflects from rigid boundary. A.K. Kapila and D.W. Schwendeman Rensselaer Polytechnic Institute