TY - CONF
T1 - Ignition and combustion of aluminum particles in shocked H2O/O2/Ar and CO2/O2/Ar mixtures
AU - Servaites, James C.
AU - Burton, R. L.
AU - Melcher, J. C.
AU - Krier, Herman
N1 - Funding Information:
This work is funded by the Ballistic Missile Defense Organization through the Office of Naval Research contract N00014-95-1-1339, and is part of the University of Illinois at Urbana-Champaign Multi-disciplinary University Research Initiative (MURI) center for the study of Novel Energetic Materials. SEM images were made with the assistance of Vania Petrova in the Center for Microanalysis of Materials, UIUC, which is supported by the U.S. Department of Energy under grant DEFG02 to 96-ER45439. Prof. N. Glumac, Department of Mechanical and Industrial Engineering, UIUC, was very helpful in the interpretation of our oxide atomic spectra; his previous work ([18]) was also utilized. Prof. A. Scheeline of UIUC provided spectroscopic advice and insight. Prof. K. S. Suslick of UIUC and Prof. A. Fontijn of Rensselaer Polytechnic Institute provided insight into the chemistry involved in aluminum reactions. We would like to acknowledge assistance in operating the shock tube by undergraduate research assistants Hadas Ritz, Carolina Lopez, and Evgeniy Sklyanskiy.
PY - 2000
Y1 - 2000
N2 - Small aluminum particles (5-10 μm) are ignited in atmospheres consisting of Ar and varying amounts of H2O, CO2, and O, at the endwall of a shock tube to study the burning characteristics in various combinations of these oxidizers. A reflected shock is used to obtain pressures of ~8.5 atm. and temperatures of ~2600 K. Visible wavelength emission spectra are recorded using a spectrometer coupled to a streak camera, and two photodetectors record intensity versus time at AIO emission wavelengths of 486 and 514 nm. The streak camera allows recording of multiple time-resolved spectra at rates of 100 μs per spectrum. Aluminum particles ignited in mixtures of CO2/O2/Ar exhibited a burn time of about one half that of an atmosphere containing only a mixture of O2/Ar, holding the argon constant at 40%. In addition, as CO, was substituted for O, in successive experiments, a non-linear relationship was observed for ignition delay time and burn time. Within mixtures of H2O/O2/Ar, two distinct burning stages are visible for the combusting aluminum particles. As an increasing amount of H2O was substituted for O2 in separate tests, a second distinct burning stage developed. Spectroscopic data recorded during such experiments portray AIO emission during both combustion stages. Aluminum particles combusted in a mixture of H2O/Ar show burn times 2-5 times greater than those from CO2/O2/Ar mixtures, and ignition delay times 3-6 times greater.
AB - Small aluminum particles (5-10 μm) are ignited in atmospheres consisting of Ar and varying amounts of H2O, CO2, and O, at the endwall of a shock tube to study the burning characteristics in various combinations of these oxidizers. A reflected shock is used to obtain pressures of ~8.5 atm. and temperatures of ~2600 K. Visible wavelength emission spectra are recorded using a spectrometer coupled to a streak camera, and two photodetectors record intensity versus time at AIO emission wavelengths of 486 and 514 nm. The streak camera allows recording of multiple time-resolved spectra at rates of 100 μs per spectrum. Aluminum particles ignited in mixtures of CO2/O2/Ar exhibited a burn time of about one half that of an atmosphere containing only a mixture of O2/Ar, holding the argon constant at 40%. In addition, as CO, was substituted for O, in successive experiments, a non-linear relationship was observed for ignition delay time and burn time. Within mixtures of H2O/O2/Ar, two distinct burning stages are visible for the combusting aluminum particles. As an increasing amount of H2O was substituted for O2 in separate tests, a second distinct burning stage developed. Spectroscopic data recorded during such experiments portray AIO emission during both combustion stages. Aluminum particles combusted in a mixture of H2O/Ar show burn times 2-5 times greater than those from CO2/O2/Ar mixtures, and ignition delay times 3-6 times greater.
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M3 - Paper
AN - SCOPUS:84894335254
T2 - 35th Intersociety Energy Conversion Engineering Conference and Exhibit 2000
Y2 - 24 July 2000 through 28 July 2000
ER -