Ignition in Solid Energetic Materials Due to Electrical Discharge

摘要

Fatal mishaps have been blamed on accidental ignition of solid rocket propellantby electrostatic discharge (ESD). To determine the physics of electrically-induced ignition, the temperature, density, and size of electrical arc channels have been quantified during electrical discharge experiments on a composite solid propellant To simulate the discharge in ESD scenarios involving insulated motors, short duration electrical discharges (50 to 400 ns) were employed. Measurements from pressure transducers and infrared detectors were consistent with a relatively slow thermally-induced reaction rather than prompt ignition from a shock wave. A high-speed framing camera observed expansion of the arc channel as electrical energy was deposited. An analytical model was adapted to predict arc channel expansion for various discharge profiles. An ignition model based on energy transport, via radiation and thermal conduction, from the plasma to the surrounding energetic constituents is proposed. A one-dimensional thermal-chemical kinetics code, XCHEM, was used to demonstrate the importance of radiation in the ignition model.