ARTICLE:

• EFFECTS OF LINE DOPPLER SHIFT ON INFRARED RADIATION IN HIGH VELOCITY FLOWS  download article

Laurent Pierrot
Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR 288 du CNRS et de l'ECP. Ecole Centrale Paris, 92295 Chatenay-Malabry Cedex, France

Anouar Soufiani
Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR 288 du CNRS et de l'ECP. Ecole Centrale Paris, 92295 Chatenay-Malabry Cedex, France

Jean Taine
Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR 288 du CNRS et de l'ECP. Ecole Centrale Paris, 92295 Châtenay-Malabry Cedex, France

ABSTRACT

The influence of the shift of gas infrared lines due to Doppler effect on the radiation emitted by hot gaseous mixtures at high velocities and transmitted through cold gaseous columns, at rest, is studied using a line-by-line approach. It is shown that there are, at given pressure, for each line, very precise optical path conditions for which the Doppler shift effect is maximum. This effect may be important for isolated lines but decreases as the spectral band width over which results are integrated increases. In the case of a whole absorption band (CO₂ near 2.7 and 4.3 μm and H₂O near 2.7 μm), the increase in the transmitted radiation intensity is smaller than 15 % for hot gas velocities smaller than 2000 m/s and pressures greater than 0.1 atm.

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