Ignition of flare propellants using AL/NI-Nanofoils at sub-atmospheric pressure

A fast and safe ignition is substantial for an effective application of decoy flares also under sub-atmospheric pressure conditions. This study investigates the use of Al/Ni-nanofoils as liners to ignite a flare pyrolant under pressure conditions up to an altitude of 10 km. The reaction front of the nanofoil propagates with more than 8 m/s and release temperatures close to 2000 K both independent of ambient pressure. Successful ignition was demonstrated down to 30 kPa with ignition delay times ranging from 100 ms (100 kPa) to 380 ms (30 kPa). To reduce the ignition delay, a modified fixation is proposed to avoid deformation of the nanofoil during reaction and to improve the heat transfer.