TY - JOUR
T1 - A correlation for burn time of aluminum particles in the transition regime
AU - Lynch, Patrick
AU - Krier, Herman
AU - Glumac, Nick
N1 - Funding Information:
This research was sponsored by the Defense Threat Reduction Agency under contracts HDTRA1-07-1-0011 and DAAE30-1-9-0080 (Program managers William Wilson and Suhithi Peiris) and the Office of Naval Research under contract N00014-08-1-0072 (Program managers Judah Goldwasser and Daniel T. Tam). Thanks also go to Maurine Vogelsang, Priya Ghandi, Jeff Mason, Armando Bernal, and David Joyce for technical assistance. The Scanning Electron Micrographs were taken in the Frederick Seitz Materials Research Laboratory Central Facilities, University of Illinois, which are partially supported by the U.S. Department of Energy under Grant DEFG02-91-ER45439.
PY - 2009
Y1 - 2009
N2 - A study of the combustion times for aluminum particles in the size range of 3-11 μm with oxygen, carbon dioxide, and water vapor oxidizers at high temperatures (>2400 K), high pressures (4-25 atm), and oxidizer composition (15-70% by volume in inert diluent) in a heterogeneous shock tube has generated a correlation valid in the transition regime. The deviation from diffusion limited behavior and burn times that could otherwise be accurately predicted by the widely accepted Beckstead correlation is seen, for example, in particles below 20 μm, and is evidenced by the lowering of the diameter dependence on the burn time, a dependence on pressure, and a reversal of the relative oxidizer strengths of carbon dioxide and water vapor. The strong dependence on temperature of burn time that is seen in nano-Al is not observed in these micron-sized particles. The burning rates of aluminum in these oxidizers can be added to predict an overall mixture burnout time adequately. This correlation should extend the ability of modelers to predict combustion rates of particles in solid rocket motor environments down to particle diameters of a few microns.
AB - A study of the combustion times for aluminum particles in the size range of 3-11 μm with oxygen, carbon dioxide, and water vapor oxidizers at high temperatures (>2400 K), high pressures (4-25 atm), and oxidizer composition (15-70% by volume in inert diluent) in a heterogeneous shock tube has generated a correlation valid in the transition regime. The deviation from diffusion limited behavior and burn times that could otherwise be accurately predicted by the widely accepted Beckstead correlation is seen, for example, in particles below 20 μm, and is evidenced by the lowering of the diameter dependence on the burn time, a dependence on pressure, and a reversal of the relative oxidizer strengths of carbon dioxide and water vapor. The strong dependence on temperature of burn time that is seen in nano-Al is not observed in these micron-sized particles. The burning rates of aluminum in these oxidizers can be added to predict an overall mixture burnout time adequately. This correlation should extend the ability of modelers to predict combustion rates of particles in solid rocket motor environments down to particle diameters of a few microns.
KW - Aluminum combustion
KW - Burn time
KW - Transition regime
UR - http://www.scopus.com/inward/record.url?scp=61849086121&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=61849086121&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2008.06.205
DO - 10.1016/j.proci.2008.06.205
M3 - Conference article
AN - SCOPUS:61849086121
SN - 1540-7489
VL - 32 II
SP - 1887
EP - 1893
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
T2 - 32nd International Symposium on Combustion
Y2 - 3 August 2008 through 8 August 2008
ER -