This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Microgravity Flame Spread over Non-Charring Materials in Exploration Atmospheres: Pressure, Oxygen, and Velocity Effects on Concurrent Flame Spread
Technical Paper
2009-01-2489
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The objective of this work is to determine the dependence of microgravity flame spread on ambient pressure, oxygen concentration, and velocity typical in exploration spacecraft and habitats. Since it is impractical to test a wide range of materials, these characteristics are being determined for major classes of materials. In the current work, a non-charring thin fuel (25-micron thick Shinkolite™ast;) was tested in microgravity to compare with previous results with a charring thin fuel. Microgravity concurrent flame spread tests were performed in a low-speed flow tunnel to simulate spacecraft ventilation flows (7–31 cm/s). The tunnel atmosphere pressure and oxygen concentration was varied over a wide range (21–85% O2, 5–16 psia).
Flame spread rate was measured to develop correlations that capture the effects of flow velocity, oxygen concentration, and pressure on the spread rate. The non-charring fuel exhibited a linear dependence on flow, similar to the charring fuel. However, the non-charring fuel had a weaker dependence on oxygen (square root versus linear for the charring fuel). The non-charring fuel was independent of pressure, unlike the square root dependence on pressure found for the charring fuel. These results demonstrate that the effect of spacecraft atmosphere on concurrent flame spread depends on the class of material, so it would be prudent to develop fire safety protocols based on the most hazardous of the different correlations. The stronger dependence on oxygen concentration for both charring and non-charring fuels shows that the lower ambient pressure planned for exploration spacecraft and habitats does not offset the increased hazard of elevated oxygen.
Authors
Citation
Olson, S. and Ruff, G., "Microgravity Flame Spread over Non-Charring Materials in Exploration Atmospheres: Pressure, Oxygen, and Velocity Effects on Concurrent Flame Spread," SAE Technical Paper 2009-01-2489, 2009, https://doi.org/10.4271/2009-01-2489.Also In
References
- Campbell, P.D., “Recommendations for Exploration Spacecraft Internal Atmospheres: The Final Report of the NASA Exploration Atmospheres Working group” JSC-63309 2006
- Olson, S.L., Ruff, G. Miller, F.J., 2008 “Microgravity Flame Spread in Exploration Atmospheres: Pressure, Oxygen, and Velocity Effects on Opposed and Concurrent Flame Spread SAE Int. J. Aerosp 1 1 239 246
- Takahashi, S., Kondou, M., Wakai, K. Bhattacharjee, S; “Effect of Radiation Loss on Flame Spread over a Thin PMMA Sheet in Microgravity” 2002 Proceedings of the Combustion Institute Volume 29 2579 2586
- Olson, S.L Miller, F.J. 2009 “Experimental Comparison of Opposed and Concurrent Flame Spread in a Forced Convective Microgravity Environment” Proceedings of the Combustion Institute V. 32 2445 2452
- Klimek, R. Wright, T. http://microgravity.grc.nasa.gov/spotlight/ 2005
- Ferkul, P.V.; “A Model of Concurrent Flow Flame Spread Over a Thin Solid Fuel” NASA CR-191111 1993
- Loh, H.-T.; “Concurrent Flow Flame Spread Study” NIST-GCR-92-603 1992
- Olson, S. L. 1991 “Mechanisms of Microgravity Flame Spread Over a Thin Solid Fuel: Oxygen and Opposed flow Effects” Combustion Science and Technology 76 4–6 233 249
- Kashiwagi, T. Ohlemiller, T.J. 1982 “A Study of Oxygen Effects on Nonflaming Transient Gasification of PMMA and PE during Thermal Irradiation,” Proceedings from the 19 th International Symposium on Combustion, The Combustion Institute 815 823
- Olson, S.L., T'ien, J.S.; 1999 “Near-Surface Vapor Bubble Layers in Buoyant Low Stretch Burning of Polymethylmethacrylate,” Fire Mater 23 227 237