Model of nonequilibrium emissivity of diatomic molecules averaged over the rotational structure


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The derivation of the calculated relations of the model of the emissivity of the electronic vibrational bands of diatomic molecules averaged over the rotational structure is presented. The model is based on the use of an ab-initio expression for the integral radiation emission coefficient of the rotational line of an electron-vibrational-rotational quantum transition and the results of ab-initio calculations of the Einstein coefficients of rovibronic quantum transitions of spontaneous emission.
Calculation formulas are obtained for the averaged emissivity coefficients of heteronuclear molecules. Their validity is shown for homonuclear molecules, including states of different symmetries, in the spectra of which alternating intensities of the emission of rotational lines are observed.
Using the obtained relations, spectra of nonequilibrium radiation from the shock wave relaxation zone were obtained in shock wave experiments in air at a speed of 7.3 km/s and a pressure of 0.7 Torr in a low-pressure chamber. A comparison with experimental data has been made.

The derivation of the calculated relations of the model of the emissivity of the electronic vibrational bands of diatomic molecules averaged over the rotational structure is presented. The model is based on the use of an ab-initio expression for the integral radiation emission coefficient of the rotational line of an electron-vibrational-rotational quantum transition and the results of ab-initio calculations of the Einstein coefficients of rovibronic quantum transitions of spontaneous emission. Calculation formulas are obtained for the averaged emissivity coefficients of heteronuclear molecules. Their validity is shown for homonuclear molecules, including states of different symmetries, in the spectra of which alternating intensities of the emission of rotational lines are observed. Using the obtained relations, spectra of nonequilibrium radiation from the shock wave relaxation zone were obtained in shock wave experiments in air at a speed of 7.3 km/s and a pressure of 0.7 Torr in a low-pressure chamber. A comparison with experimental data has been made.

DOI: http://doi.org/10.33257/PhChGD.24.6.1078


Volume 24, issue 6, 2023 year


Модель усредненной по вращательной структуре неравновесной излучательной способности двухатомных молекул

Представлен вывод расчетных соотношений модели усредненной по вращательной структуре излучательной способности электронно-колебательных полос двухатомных молекул. Модель основана на использовании ab-initio выражения для интегрального коэффициента испускания излучения вращательной линии электронно-колебательно-вращательного квантового перехода и результатов ab-initio расчетов коэффициентов Эйнштейна ровибронных квантовых переходов спонтанного излучения.
Расчетные формулы получены для усредненных коэффициентов излучения гетероядерных молекул. Показана их справедливость для гомоядерных молекул, в том числе для состояний разной симметрии, в спектрах которых наблюдается чередование интенсивностей излучения вращательных линий.
С использованием полученных соотношений получены спектры неравновесного излучения релаксационной зоны ударной волны в ударно-волновых экспериментах в воздухе при скорости 7.3 км/с и давлении 0.7 Торр в камере низкого давления. Выполнено сравнение с экспериментальными данными.

неравновесное излучение сильных ударных волн, спектральная излучательная способность двухатомных молекул, излучательная способность усредненная по вращательной структуре электронно-колебательно-вращательных переходов

DOI: http://doi.org/10.33257/PhChGD.24.6.1078


Volume 24, issue 6, 2023 year



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