Thermal response characteristics of DNAN explosive in a real fire environment

The structure containing explosives may encounter different fire scenarios in application. The influence factors of flame radiant heat flow are numerous and the control mechanism is complex due to the complexity and diversity of fire scenes. It is necessary to identify key physical quantities, analyze the controlling mechanism, and establish boundary heat flow load model. Several factors were considered to comprehend and assess the thermal response characteristics of ammunition in a real fire environment, including the boundary heat flow load, the combined heat transfer effect of the air inter-layer, and the thermal decomposition of energetic explosive. Numerical model and calculation method were developed, and the thermal response characteristics of ammunition exposed to fire were investigated. The results demonstrate that the ammunition's temperature rise increases non-linearly as the thickness of flame engulfment increases. Conversely, the temperature rise decreases non-linearly as distance from the fire source increases. In terms of initiation delay time, it decreases non-linearly as the thickness of flame engulfment increases. However, initiation delay time increases non-linearly as distance from the fire source increases. A comprehensive model that considers real fire environment is crucial for prompt and accurate interventions, when assessing the thermal safety of ammunition in complex fire scenarios.