Picosecond CARS measurements of nitrogen rotational/translational and vibrational temperature in a nonequilibrium Mach 5 flow
Picosecond CARS measurements of nitrogen rotational/translational and vibrational temperature in a nonequilibrium Mach 5 flow
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非平衡马赫 5 流中氮气旋转/平移和振动温度的皮秒 CARS 测量
DOI：
10.1007/s00348-012-1422-1
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发表时间：
2012
影响因子：
2.4
通讯作者：
W. Lempert
中科院分区：
文献类型：
--
作者：
A. Montello;M. Nishihara;J. Rich;I. Adamovich;W. Lempert
Picosecond Unstable-resonator Spatially Enhanced Detection Coherent Anti-Stokes Raman Scattering (USED-CARS) is used for the measurement of nitrogen Q-branch (ΔJ= 0) spectra in the subsonic plenum and supersonic flow of a highly nonequilibrium Mach 5 wind tunnel. Spectra are processed to infer rotational/translational (Trot) and first-level vibrational (Tvib) temperatures in the 200–370 torr plenum simultaneously. Operation of the nominally high reduced electric field (E/npeak~ 500 Td), nsec pulsed discharge alone results in fairly significant vibrational loading,Tvib~ 720 K/Trot~ 380 K; addition of an orthogonal lowE/n(~10 Td) DC sustainer discharge produces substantial vibrational loading,Tvib~ 2,000 K/Trot~ 450 K. Effects of injection of CO2, NO, and H2downstream of the pulser–sustainer discharge are examined, which result in vibrational relaxation accompanied by simultaneous gas heating,Tvib~ 800–1,000 K/Trot~ 600 K. CARSk measurements within very low-density flows in the Mach 5 expansion nozzle are also performed, withTvibmeasured in both the supersonic free-stream and downstream of a bow shock created by a 5-mm-diameter cylindrical test object in the Mach 5 flow. Measurements within 300 μm of the cylinder leading edge show that for pure N2, or N2with 0.25 torr CO2injection, no vibrational relaxation is observed behind the bow shock.
DOI：
10.1007/978-3-642-61247-3
发表时间：
1991-10
期刊：
--
影响因子：
--
作者：
Iu. P. Raizer
通讯作者：
Iu. P. Raizer