Numerical modeling of gun experiments with impact velocities less than SDT threshold: Thermal explosion initiated by friction heat

One and two dimensional calculations were made to model thermal explosion ignited by friction heat, hypothesized as an initiation mechanism for the unknown XDT phenomenon that is responsible for detonations observed in gun experiments with impact velocities less than threshold for shock to detonation transition. Preliminary results suggest that friction induced thermal explosion would be quenched by cooling associated with side rarefactions after penetrating only a thin layer of the propellant. Other effects would be expected to increase the calculated heating rates or speed up the friction induced thermal explosion. For this reason, friction cannot be ruled out as an initiation mechanism on the basis of the results described.