Runaway reaction due to gas-dynamic choking in solid explosive containing a single crack

This work predicts the critical conditions required for the onset of reaction runaway in a narrow high-explosive slot intended to simulate a crack. A model is developed where slot pressurization is attributed to gas-dynamic choking at the slot exit. The combination of the choking and a pressure-dependent reaction rate is shown to be capable of predicting runaway reaction for a range of slot dimensions and pressures, even when the explosive regression is considered. This model agrees with experimental pressure measurements of reaction runaway in slots and provides a mechanism for the erratic burning observed with some explosives under high pressure.