TY - JOUR
T1 - Characteristics of O2-ar inductively coupled plasma test flow during catalytic recombination processes
AU - Osawa, Hiroshi
AU - Suzuki, Toshiyuki
AU - Takayanagi, Hiroki
AU - Mizuno, Masahito
AU - Fujita, Kazuhisa
AU - Sawada, Keisuke
N1 - Funding Information:
The present study was partly supported by the Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists (No. 20-2159). The authors would like to express sincere appreciation to K. Ueno of Tohoku University, Japan, and M. Furudate of Chungnam National University, Republic of Korea, for helpful comments and suggestions. The authors also would like to thank the Wind Tunnel Technology Center of Japan Aerospace Exploration Agency for technical support and suggestions for the present measurement. Finally, the authors would like to give special thanks to P. Boubert of Université de Rouen, France, for kindly providing the references.
PY - 2013
Y1 - 2013
N2 - The flowfield characterization in an inductively coupled plasma generator is conducted by optical emission spectroscopy and laser absorption spectroscopy as well as direct simulation Monte Carlo computation. A silicon carbide test piece is exposed to a 1-kilowatt oxygen-argon inductively coupled plasma test flow, and the emission intensity profiles of an atomic oxygen spectral line at 844.636 nm and an argon spectral line at 842.4648 nm along the central axis of the quartz tube are first obtained by optical emission spectroscopy with the surface temperature of 300, 1280, and 1430 K. By comparing the measured emission intensity profiles with the computed number density profiles, qualitative agreement is found for the case with the surface temperature of 300 K, while the difference becomes evident for the other two cases. Because the emission intensity obtained by the spectrometer is generally the integrated value along the line of sight, the measured emission intensity profile can be different from the true emission intensity profile along the central axis. Measure of the emission intensity profiles of atomic oxygen and argon in the radial direction by applying the inverse Abel transform to characterize the entire flowfield in the test chamber is attempted. It is found that the emission intensity near the quartz tube is significantly strong around the test piece not depending on the surface temperature of the test piece. Moreover, the electronic excitation temperature is evaluated through a Boltzmann plot, and it is found that it increases toward the test piece. In the direct simulation Monte Carlo computation, the measured emission intensity profiles of atomic oxygen and argon along the central axis for heating cases are qualitatively reproduced when the measured electronic excitation temperature at the exit boundary is assumed. These results show that the emission intensity profiles of atomic oxygen and argon in the entire flowfield around the test piece should be estimated by applying the inverse Abel transform for evaluating the catalytic efficiency of atomic oxygen recombination accurately.
AB - The flowfield characterization in an inductively coupled plasma generator is conducted by optical emission spectroscopy and laser absorption spectroscopy as well as direct simulation Monte Carlo computation. A silicon carbide test piece is exposed to a 1-kilowatt oxygen-argon inductively coupled plasma test flow, and the emission intensity profiles of an atomic oxygen spectral line at 844.636 nm and an argon spectral line at 842.4648 nm along the central axis of the quartz tube are first obtained by optical emission spectroscopy with the surface temperature of 300, 1280, and 1430 K. By comparing the measured emission intensity profiles with the computed number density profiles, qualitative agreement is found for the case with the surface temperature of 300 K, while the difference becomes evident for the other two cases. Because the emission intensity obtained by the spectrometer is generally the integrated value along the line of sight, the measured emission intensity profile can be different from the true emission intensity profile along the central axis. Measure of the emission intensity profiles of atomic oxygen and argon in the radial direction by applying the inverse Abel transform to characterize the entire flowfield in the test chamber is attempted. It is found that the emission intensity near the quartz tube is significantly strong around the test piece not depending on the surface temperature of the test piece. Moreover, the electronic excitation temperature is evaluated through a Boltzmann plot, and it is found that it increases toward the test piece. In the direct simulation Monte Carlo computation, the measured emission intensity profiles of atomic oxygen and argon along the central axis for heating cases are qualitatively reproduced when the measured electronic excitation temperature at the exit boundary is assumed. These results show that the emission intensity profiles of atomic oxygen and argon in the entire flowfield around the test piece should be estimated by applying the inverse Abel transform for evaluating the catalytic efficiency of atomic oxygen recombination accurately.
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U2 - 10.2514/1.T3722
DO - 10.2514/1.T3722
M3 - Article
AN - SCOPUS:84873619482
VL - 27
SP - 30
EP - 41
JO - Journal of Thermophysics and Heat Transfer
JF - Journal of Thermophysics and Heat Transfer
SN - 0887-8722
IS - 1
ER -