Hot surface ignition of Jet-A fuel by conductive deposits

• Published in: Proceedings of the Combustion Institute 2002, Vol.29 (1), p.297-303
• Main Authors: Colwell, Jeff D., Korb, Thomas M., Peck, Robert E.
• Format: Article
• Language: English
• ISSN: 1540-7489; 1873-2704
• DOI: 10.1016/S1540-7489(02)80040-2

Inspection of electrical components mounted in aircraft fuel tanks has revealed sporadic evidence of silver oxide deposits formed by corrosion. The present work shows that these deposits can lead to hot surface ignition of flammable Jet-A vapors given sufficient electrical input. A logistic regression of ignition data showed that electrical power was a relatively good predictor of ignition. Temperatures measured at the base of the deposit during iguition testing exceeded the hot surface ignition temperature of Jet-A. A thermal model of the process demonstrated that electrical power dissipation alone could produce the observed surface temperatures. The ability of the deposits to dissipate electrical power increased with the number of times the deposit had been exposed to Jet-A and voltage potential. This change in the electrical property of the deposit coincided with changes in the chemical makeup and structure of the deposit. Pristine deposits were primarily silver oxide, while deposits capable of high-power dissipation were primarily disordered and graphitic carbon with some conglomerates of silver-based material.