TY - JOUR
T1 - Laser-induced breakdown emission in hydrocarbon fuel mixtures
AU - Kobayashi, Kazunobu
AU - Bak, Moon Soo
AU - Tanaka, Hiroki
AU - Carter, Campbell
AU - Do, Hyungrok
N1 - Publisher Copyright:
© 2016 IOP Publishing Ltd.
PY - 2016/3/11
Y1 - 2016/3/11
N2 - Time-resolved emission measurements of laser-induced breakdown plasmas have been carried out to investigate the effect that gas species might have on the kinetics, particularly in excited states, and the resulting plasma properties. For this purpose, fuel-oxygen (O2)-carbon dioxide (CO2) mixtures with either helium (He) or nitrogen (N2) balance are prepared while maintaining their atomic compositions. The fuels tested in this study are methane (CH4), ethylene (C2H4), propane (C3H8), and butane (C4H10). The breakdown is produced in the mixtures (CH4/CO2/O2/He, C2H4/O2/He, C3H8/CO2/O2/He and C4H10/CO2/O2/He or CH4/CO2/O2/N2, C2H4/O2/N2, C3H8/CO2/O2/N2 and C4H10/CO2/O2/N2) at room conditions using the second harmonic of a Q-switched Nd:YAG laser (with pulse duration of 10 ns). The temporal evolution of plasma temperature is deduced from the ratio of two oxygen lines (777 nm and 823 nm) through Boltzmann analysis, while the evolution of electron number density is estimated based on Stark broadening of the Balmer-alpha (Hα) line at 656 nm and the measured plasma temperature. From the results, the temporal evolution of emission spectra and decay rates of atomic line-intensities are found to be almost identical between the breakdown plasma in the different mixtures given balancing gases. Furthermore, the temporal evolution of plasma temperature and electron number density are also found to be independent of the species compositions. Therefore, this behavior - of the breakdown emissions and plasma properties in the different mixtures with identical atomic composition - may be because the breakdown gases reach similar thermodynamic and physiochemical states immediately after the breakdown.
AB - Time-resolved emission measurements of laser-induced breakdown plasmas have been carried out to investigate the effect that gas species might have on the kinetics, particularly in excited states, and the resulting plasma properties. For this purpose, fuel-oxygen (O2)-carbon dioxide (CO2) mixtures with either helium (He) or nitrogen (N2) balance are prepared while maintaining their atomic compositions. The fuels tested in this study are methane (CH4), ethylene (C2H4), propane (C3H8), and butane (C4H10). The breakdown is produced in the mixtures (CH4/CO2/O2/He, C2H4/O2/He, C3H8/CO2/O2/He and C4H10/CO2/O2/He or CH4/CO2/O2/N2, C2H4/O2/N2, C3H8/CO2/O2/N2 and C4H10/CO2/O2/N2) at room conditions using the second harmonic of a Q-switched Nd:YAG laser (with pulse duration of 10 ns). The temporal evolution of plasma temperature is deduced from the ratio of two oxygen lines (777 nm and 823 nm) through Boltzmann analysis, while the evolution of electron number density is estimated based on Stark broadening of the Balmer-alpha (Hα) line at 656 nm and the measured plasma temperature. From the results, the temporal evolution of emission spectra and decay rates of atomic line-intensities are found to be almost identical between the breakdown plasma in the different mixtures given balancing gases. Furthermore, the temporal evolution of plasma temperature and electron number density are also found to be independent of the species compositions. Therefore, this behavior - of the breakdown emissions and plasma properties in the different mixtures with identical atomic composition - may be because the breakdown gases reach similar thermodynamic and physiochemical states immediately after the breakdown.
KW - electron number density
KW - hydrocarbon fuel
KW - laser-induced breakdown
KW - plasma temperature
KW - time-resolved emission measurement
UR - https://www.scopus.com/pages/publications/84962311447
U2 - 10.1088/0022-3727/49/15/155201
DO - 10.1088/0022-3727/49/15/155201
M3 - Article
AN - SCOPUS:84962311447
SN - 0022-3727
VL - 49
JO - Journal of Physics D: Applied Physics
JF - Journal of Physics D: Applied Physics
IS - 15
M1 - 155201
ER -
