Multiphysical Field Parameters and Energy Propagation Law of Al/PTFE Shell Loose Charge Deflagration Reaction

Aluminum/polytetrafluoroethylene (Al/PTFE) is a new type of composite material with high-energy content. The combination of high-energy density of aluminum and high-temperature stability of polytetrafluoroethylene makes the energetic material have the characteristics of insensitive, thermal stability, and high energy. In order to explore the propagation law of acoustic, electromagnetic, and overpressure multiphysical fields during the deflagration reaction of Al/PTFE energetic materials, and to obtain the propagation law of acoustic, optical, and electromagnetic energy, this article takes the Al/PTFE energetic material mixture under the condition of loose shielding charge as the research object. Based on the self-built deflagration-induced multiphysical field response test system, the Al/PTFE energetic material mixture (the mass percentage of Al and PTFE is 26.5%/73.5%) with different charge masses (4.0, 5.7 g) was excited by electric ignition to carry out deflagration reaction in a closed environment. At the same time, the propagation process of acoustic, electromagnetic, and overpressure signals in the deflagration process is numerically simulated. The results show that the sound energy per unit area is inversely proportional to the square of the distance from the explosion center, and the energy concentration frequency of the sound pressure signal moves to the high-frequency direction with the increase of the distance from the explosion center. The time evolution law of visible light radiation energy flux density conforms to the trend of three sine functions. The electric field energy is inversely proportional to the 2.8–3.4 power of the distance from the explosion center, and the magnetic field energy is inversely proportional to the 6.56–6.57 power of the distance from the explosion center.