Analysis of the Influence of Grooved Structures and Thermal Barriers on the Thermal Response of Ammunition Under Thermal Coupling Effects

To evaluate the reliability and safety of ammunition, it is necessary to investigate its thermal response characteristics following thermal protection treatment. This paper discusses two thermal protection design schemes for ammunition under thermo-coupling calculation methods: grooved structures and thermal interface materials. First, addressing accidental internal energy release ignition during transport and storage, pre-formed grooves are designed based on fragment size after shell ignition combustion. These grooves rupture prematurely upon reaching ignition temperature to release energy. Second, a controlled-release safety design for internal and external thermal insulation materials is implemented. By establishing an air physical interface, the study investigates how changes in charge quantity and physical interface size affect thermal response under different heating directions while maintaining a constant aspect ratio of the warhead propellant. Based on these findings, single-layer and composite flame-retardant coating inert interfaces are configured. By varying the thickness of the inner and outer coating interfaces, the optimal thickness for achieving thermal protection under different heating directions is explored. Results indicate that 6mm×13mm pre-machined grooves significantly reduce post-ignition explosion risks. Optimal thicknesses exist for both air interfaces and thermal insulation coatings under different heating directions: - Bidirectional heating: Inner 4mm, Outer 2mm - Lateral heating: Inner 4.5mm, Outer 2mm - Vertical heating: Inner 3.5-4mm, Outer 2mm Compared to uncoated and single-layer coatings, these configurations achieve: - Up to 14% higher ignition temperatures - Ignition time delays of up to 1648%.