MODELLING THE IGNITION OF PYROTECHNIC COUNTERMEASURE DECOY FLARES

Rapid and effective ignition of pyrotechnic countermeasure decoy flares is vitally important to the safety of expensive military platforms such as aircraft. QinetiQ is conducting experimental and theoretical research into pyrotechnic countermeasure decoy flares. A key part of this work is the development of advanced ignition models to improve the understanding of the ignition processes occurring for these flares. Typically, these flares are wrapped in a material such as foil. Until this material bursts or ruptures, the flare can be considered to be effectively a closed system. Therefore it is possible to use gun internal ballistics models to investigate the ignition and combustion processes in these flares. An intensive modelling work programme, closely supported by experiments to provide data for and to validate the modelling, was undertaken for a baseline pyrotechnic flare. The modelling investigated the main heat transfer processes to determine the dominant energy transfer modes and ways by which the ignition delay of the flares could be decreased. This paper describes the computer modelling and experiments conducted to validate the predictions.