Abstract
In order to secure fire safety over the entire period of a manned space mission, gaining a systematic understanding of the effects of gravity on flame spread is important. In this study, opposed-flow flame spread along a thermally thin combustible solid for different sample orientations (−20° downward, horizontal, and +20° upward) was experimentally investigated by changing the ambient oxygen concentration and gravity level. The flame spread rate decreases with decreasing oxygen concentration under normal gravity, and its rate at 18 % oxygen concentration is equivalent to that at 21 % oxygen concentration under microgravity. The downward flame spread rate decreases with an increase in gravity. In contrast, the horizontal and the +20° upward flame spread rates clearly increase as the gravity level increases. The flame spread rate varies remarkably with sample orientation in a supergravity environment. To clarify the effect of gravity on flame spread, the relation between the non-dimensional flame spread rate and the Rayleigh number was examined. The Ra number both for horizontal and upward flame spread increases with increasing gravity, while the Ra number for downward flame spread decreases slightly with a decrease in gravity. The non-dimensional flame spread rate is almost constant under normal and supergravity conditions for Ra numbers less than 103 and is equivalent to that under microgravity. When the Ra number is greater than 103, the non-dimensional flame spread rate increases with increasing Ra number and is proportional to Ra1/3.
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Abbreviations
- A:
-
The thermal diffusivity of oxidizer
- a s :
-
The thermal diffusivity of paper
- g :
-
The gravity level g = 1 on Earth
- g :
-
Acceleration due to gravity
- L :
-
The flame length defined as spreading base flame
- Ra:
-
The Rayleigh number
- T f :
-
The averaged temperature in flame zone
- T 0 :
-
The ambient temperature
- U :
-
The averaged opposed airflow velocity
- V :
-
The flame spread rate
- V n :
-
The non-dimensional flame spread rate
- X O2 :
-
The volumetric oxygen concentration
- β :
-
The thermal coefficient of volume expansion
- ν:
-
The kinematic viscosity
- θ :
-
The sample orientation angle
- δ :
-
The sample thickness
References
Kimzey, J.H.: Proceedings of the 3rd Space Processing Symposium, NASA Space Flight Center, M-74-5, NASA TM-X-70752, 1, pp. 115–130 (1974)
Olson, S.L.: The effect of microgravity on flame spread over a thin fuel, NASA TM-100195 (1987)
Friedman, R., Urban, D.L.: Contributions of microgravity test results to the design of spacecraft fire-safety systems, AIAA paper 93–1152 (1993)
Shipp, M., Spearpoint, M.: The detection of fires in micro-gravity, fire safety science. In: Proceedings of the 4th International Symposium, IAFSS, pp. 739–750 (1994)
Ramachandra, P.A., Altenkirch, R.A., Bhattacharjee, S., Tang, L., Sacksteader, K., Wolverton, M.K.: The behavior of flames spreading over thin solids in microgravity. Combust. Flame 100, 71–84 (1995)
Bryant D., Judd, M.D.: Proceedings of the 10th Anniversary of First ESA Parabolic Flight Campaign Workshop, ESA, pp. 99–101 (1995)
Sanchez Tafira, C., Linan, A., Salva, J.A., Conchero, G., Juste, G.L., Esteban, F.: Combustion Experiments During KC-135 Parabolic Flights, ESA SP-1113, pp. 53–64 (1989)
West, J., Tang, L., Altenkirch, R.A., Bhattacharjee, S., Sacksteader, K., Delichatsios, M.A.: Quiescent flame spread over thick fuels in microgravity. Proc. Combust. Inst. 26, 1335–1343 (1996)
Kashiwagi, T., MCgrattan, K.B., Olson, S.L., Fujita, O., Kikuchi, M., Ito, K.: Effect of slow wind on localized radiative ignition and transition to flame spread in microgravity. Proc. Combust. Inst. 26, 1345–1352 (1996)
Altenkirch, R.A., Tang, L., Sacksteader, K., Bhattacharjee, S., Delichatsios, M.A.: Inherently unsteady flame spread to extinction over thick fuels in microgravity. Proc. Combust. Inst. 27, 2515–2524 (1998)
Takahashi, S., Kondou, M., Wakai, K., Bhattacharjee, S.: Effect of radiation loss on flame spread over a thin PMMA sheet in microgravity. Proc. Combust. Inst. 29, 2579–2586 (2002)
Bhattacharjee, S., Ayala, R., Wakai, K., Takahashi, S.: Opposed-flow flame spread in microgravity-theoretical prediction of spread rate and flammability map. Proc. Combust. Inst. 30, 2279–2286 (2005)
Sacksteader, K.R., Pettegrew, R.D., T’ien J.S.: Flame spreading over thin fuel samples in partial gravity environments, AIAA paper 98–0567 (1998)
Takahashi, K., Kodaira, Y., Kudo, Y., Ito, A., Saito, K.: Effect of oxygen on flame spread over liquids. Proc. Combust. Inst. 31, 2625–2631 (2007)
Sato, K, Suzuki, K., Sakai, Y., Sega, S.: Effects of flame retardant on the behavior and temperature profiles of flames spreading over paper, fire safety science. In: Proceedings of the 4th International Symposium, IAFSS, pp. 503–514 (1994)
Acknowledgments
This study was supported by “Ground-based Research Program for Space Utilization” promoted by Japan Space Forum. We would like to thank T. Nagata, A. Nagadoi, S. Oikawa, T. Okizaki, and Y. Kazehare for their help in experiments and preparing the manuscript.
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Torikai, H., Ito, A., Kudo, Y. (2015). Section B Fire and Explosion - Effect of Gravity on Flame Spread Along a Thin Combustible Solid for Different Sample Orientations in Opposed Flow. In: Saito, K., Ito, A., Nakamura, Y., Kuwana, K. (eds) Progress in Scale Modeling, Volume II. Springer, Cham. https://doi.org/10.1007/978-3-319-10308-2_10
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DOI: https://doi.org/10.1007/978-3-319-10308-2_10
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