TY - JOUR
T1 - Realizing microgravity flame spread characteristics at 1 g over a bed of nano-aluminum powder
AU - Malchi, J. Y.
AU - Prosser, J.
AU - Yetter, R. A.
AU - Son, S. F.
N1 - Funding Information:
This work was sponsored by the U.S. Army Research Office under the Multi-University Research Initiative under Contract No. W911NF-04-1-0178. The support and encouragement provided by Dr. Ralph Anthenion of the Army Research Office is gratefully acknowledged. The authors thank Dr. Paul Ronney from University of Southern California for the inspiring discussions at the 31st International Symposium on Combustion.
PY - 2009
Y1 - 2009
N2 - Nanoscale aluminum (nAl) powders demonstrate relatively fast counter-flow flame spread rates compared to typical fuels such as Poly(methyl methacrylate) or cellulose at similar conditions. This allows for the dominant forward heat transfer mechanism to be through the solid fuel at higher applied oxidizer velocities, and flame structure characteristics typically observed in microgravity to be realized at 1 g conditions. Because of the porosity of the nAl powder, the gaseous oxidizer can diffuse into the bed and reactions within the solid phase become important. Using an energy balance applied to only the solid phase, an analytical model is developed which predicts the experiments for flame spread over a nAl bed. Moreover, an explanation for fingering phenomenon is established based on the effective Lewis and Damköhler numbers. This allows for an explanation of why flame spread over a bed of nAl will demonstrate this fingering instability in a quiescent, 1 g environment without a top plate to hinder buoyant flows.
AB - Nanoscale aluminum (nAl) powders demonstrate relatively fast counter-flow flame spread rates compared to typical fuels such as Poly(methyl methacrylate) or cellulose at similar conditions. This allows for the dominant forward heat transfer mechanism to be through the solid fuel at higher applied oxidizer velocities, and flame structure characteristics typically observed in microgravity to be realized at 1 g conditions. Because of the porosity of the nAl powder, the gaseous oxidizer can diffuse into the bed and reactions within the solid phase become important. Using an energy balance applied to only the solid phase, an analytical model is developed which predicts the experiments for flame spread over a nAl bed. Moreover, an explanation for fingering phenomenon is established based on the effective Lewis and Damköhler numbers. This allows for an explanation of why flame spread over a bed of nAl will demonstrate this fingering instability in a quiescent, 1 g environment without a top plate to hinder buoyant flows.
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U2 - 10.1016/j.proci.2008.09.007
DO - 10.1016/j.proci.2008.09.007
M3 - Conference article
AN - SCOPUS:61849161552
SN - 1540-7489
VL - 32 II
SP - 2437
EP - 2444
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 2
T2 - 32nd International Symposium on Combustion
Y2 - 3 August 2008 through 8 August 2008
ER -