每年出版 6 期
ISSN 打印: 2150-766X
ISSN 在线: 2150-7678
Indexed in
INVESTIGATION OF THE USE OF CARBON NANOTUBE NOx SENSORS FOR THE HEALTH MONITORING OF NITRATE ESTER PROPELLANTS
摘要
The chemical aging mechanism of minimum smoke or nitrate ester propellants loosely consists of the decomposition of the energetic plasticizer leading to the eventual production of various gasses to include NOx, and CO2. When the rate of production of these gasses exceeds the rate of diffusion to propellant-free surfaces, gas accumulation in intermolecular free space can lead to propellant cracking and/or autocatalytic ignition of the propellant grain. To limit the rate of production of these gases and to extend the useful service life of these propellant systems, stabilizers such as N-methyl-4-nitroaniline or 2-nitro-diphenylamine are added to react with the intermediate decomposition species to produce a thermally stable and nongaseous compound. Service life monitoring then consists of destructive testing of samples of motors of various ages from the population in question whereby the rate of stabilizer depletion is measured and the remaining service life is projected based on the estimated time for the stabilizer level to fall below an accepted minimum level. This paper presents a nondestructive approach and preliminary results for the use of carbon nanotube gas sensors for the health monitoring of nitrate ester propellants. Gas sensors placed in the bore or canister of individual motors will monitor the partial pressure and rate of production of decomposition gas products. The rate of evolution of NOx is correlated to the remaining stabilizer in the propellant.
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Simmons David R., Marotta Stephen A., Return-on-Investment potential for US Army missile health monitoring, 2014 International Conference on Prognostics and Health Management, 2014. Crossref