Simulation of the ignition of organic explosives by a laser pulse in the weak absorption region

Abstract

Numerical simulation of the ignition of RDX, HMX, and TATB by a nanosecond laser pulse was performed. The heat-conduction equation was solved in cylindrical coordinates with allowance for the multiple reflection of the light beam, a zero-order exothermic reaction, and melting. Despite the small temperature gradient due to the smallness of the radiation absorption coefficient, violation of thermal equilibrium due to Arrhenius nonlinearity leads to ignition of energetic materials from the surface. The critical energy density for ignition of PETN, RDX, HMX, and TATB by a nanosecond laser pulse was determined. Calculations have shown that with identical absorption and reflection coefficients, PETN is the most sensitive and TATB is the most heat-resistant.