IGNITION AND COMBUSTION OF PYROTECHNICS AT LOW PRESSURES AND AT TEMPERATURE EXTREMES

摘要

Rapid and effective ignition of pyrotechnic countermeasure decoy flares is vitallyimportant to the safety of expensive military platforms such as aircraft. QinetiQ isconducting experimental and theoretical research into pyrotechnic countermeasuredecoy flares. A key part of this work is the development and application ofimproved models to increase the understanding of the ignition processes occurringfor these flares. These models have been implemented in a two-dimensionalcomputational model and details are described in this paper. Previous work hasconducted experiments and validated the computational model at ambienttemperature and pressure. More recently the computational model has beenvalidated at pressures down to that equivalent to 40,000 feet but at ambienttemperature (～290K). This paper describes further experimental work in which theignition delays of the priming material in inert countermeasure decoy flares weredetermined for pressures down to 40,000 feet and at temperature extremes of -40°C and 100°C. Also included in this paper is a comparison of the measured andpredicted ignition delays at low pressures and temperature extremes. Theagreement between the predicted and measured ignition delays is acceptable. Thispaper is an extended abstract – the full paper appears in Defence Technology,Volume 13, Number 3.