Ullage Tank Fuel-Air Mixture Characterisation.
Scientific Publication
- Report Number:
- DSTO-TN-1059
- Authors:
- Armitt, D.; Skibinksi, C.
- Issue Date:
- 2011-12
- AR Number:
- AR-015-192
- Classification:
- Unclassified
- Report Type:
- Technical Note
- Division:
- Weapon Systems Division (WSD)
- Release Authority:
- Chief, Weapons Systems Division
- Task Sponsor:
- DMO
- Task Number:
- DMO 07/223
- File Number:
- 2011/1051172/1
- Pages:
- 44
- References:
- 26
- Terms:
- Aviation fuel; Fuel tanks; Characterisation
- URI:
- http://hdl.handle.net/1947/10176
Abstract
This technical note discusses method development for the gas chromatography/mass spectrometry (GC/MS) vapour characterisation of Jet A-1 fuel. The vapour characterisation was conducted in the ullage; the void volume above the liquid fuel. A key objective was to determine the relative headspace concentrations, of different compounds at various equilibrium temperatures. This study was conducted to further understand the mechanisms of flame propagation in fuel tank vulnerability tests under experimental conditions that reflect the field environment of aviation fuel tanks used by the Australian Defence Force (ADF). The results showed that the major constituents were 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, decane and undecane. Equilibrium was reached in the system after 10 minutes of incubation regardless of the temperature.
Executive Summary
The aim of the project was to develop a reproducible gas chromatography/mass spectrometry (GC/MS) method to characterise samples of Jet A-1 fuel, to further understand the mechanisms of flame propagation in fuel tank vulnerability tests.; The characterisation of the fuel involved:; i. GC/MS method development to determine instrumental and sampling variables,; ii. Characterisation of liquid and vapour fuel samples using mass spectral libraries and standard reference samples, and; iii. Establishing a quality control procedure to confirm the integrity of the characterisation.; The experimental conditions reflected the field conditions of aviation fuel tanks used by the Australian Defence Force (ADF). Extensive experimentations were conducted for various fuel sample temperatures and equilibrium times, as these parameters were considered to be the most significant for vapour characterisation. Other variables that were not able to be tested include sample volume, fuel-air ratio and location of sampling fibre in test cell. Investigation of these parameters is recommended for future work in the area.; The results, from the chromatograms, show that the major constituents included 1,2,4-trimethylbenzene, 1,3,5 trimethylbenzene, decane and undecane. The method developed was found to not only characterise a considerable portion of the fuel sample, but also to exhibit excellent reproducibility. Quality control measures established that the gas chromatogram peak areas were within a difference of 1.55% for the liquid sample and 2.08% for the vapour sample after three consecutive analyses.