TY - GEN
T1 - The effect of pre-heating on flame propagation in nanocomposite thermites
AU - Dikici, Birce
AU - Pantoya, Michelle L.
N1 - Funding Information:
The authors gratefully acknowledge support from the Army Research Office contract W911NF-04-1-0217 (program director Dr. Ralph Anthenien), Office of Naval Research contract N000140810104 (program director Dr. Clifford Bedford), and National Science Foundation grant CBET-0755236.
PY - 2009
Y1 - 2009
N2 - Flame propagation in a confined tube configuration was evaluated for aluminum (Al) and molybdenum trioxide (MoO3) thermites starting at room temperature and preheated up to 170°C. Flame propagation was analyzed via high speed imaging diagnostics and temperatures were monitored with thermocouples. Experiments were performed in an air-ambient reaction chamber at standard atmosphere pressure. Thermites were ignited using a Nichrome wire thermal ignition source. The flame propagation behavior for the nanocomposite thermite was compared to micron composite thermite of the same composition. Results indicate that increasing the initial temperature of the reactants results in dramatically increased flame speeds for nanocomposite thermite (i.e., from 630 to 1061 m/s for ambient and 105°C preheat temperature, respectively) and for micron composite thermite (i.e., from 251 to 544 m/s) samples. Experimental studies were extended giving a cooling time for the heated thermites prior to ignition and flame propagation. It is shown that when 105°C heated thermites are cooled; they propagate at the same rate as ambient temperature thermites. However, thermites cooled from 170°C demonstrate a reduction in propagation rate (around 21% for micron and 4% for nano composite thermites) compared to non-preheated case.
AB - Flame propagation in a confined tube configuration was evaluated for aluminum (Al) and molybdenum trioxide (MoO3) thermites starting at room temperature and preheated up to 170°C. Flame propagation was analyzed via high speed imaging diagnostics and temperatures were monitored with thermocouples. Experiments were performed in an air-ambient reaction chamber at standard atmosphere pressure. Thermites were ignited using a Nichrome wire thermal ignition source. The flame propagation behavior for the nanocomposite thermite was compared to micron composite thermite of the same composition. Results indicate that increasing the initial temperature of the reactants results in dramatically increased flame speeds for nanocomposite thermite (i.e., from 630 to 1061 m/s for ambient and 105°C preheat temperature, respectively) and for micron composite thermite (i.e., from 251 to 544 m/s) samples. Experimental studies were extended giving a cooling time for the heated thermites prior to ignition and flame propagation. It is shown that when 105°C heated thermites are cooled; they propagate at the same rate as ambient temperature thermites. However, thermites cooled from 170°C demonstrate a reduction in propagation rate (around 21% for micron and 4% for nano composite thermites) compared to non-preheated case.
UR - http://www.scopus.com/inward/record.url?scp=78549247123&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:78549247123
SN - 9781563479694
T3 - 47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
BT - 47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
T2 - 47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
Y2 - 5 January 2009 through 8 January 2009
ER -