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Vibrational energy relaxation in shock-heated CO/N2/Ar mixtures.
- Source :
- Journal of Chemical Physics; 6/14/2024, Vol. 160 Issue 22, p1-16, 16p
- Publication Year :
- 2024
-
Abstract
- Experimental and numerical studies were performed on the vibrational energy relaxation in shock-heated CO/N<subscript>2</subscript>/Ar mixtures. A laser absorption technique was applied to the time-dependent rovibrational temperature time-history measurements. The vibrational relaxation data of reflected-shock-heated CO were summarized at 1720–3230 K. In shock-tube experiments, the rotational temperature of CO quickly reached equilibrium, whereas a relaxation process was found in the time-dependent vibrational temperature. For the mixture with 1.0% CO and 10.0% N<subscript>2</subscript>, the vibrational excitation caused a decrease in the macroscopic thermodynamic temperature of the test gas. In the simulations, the state-to-state (StS) approach was employed, where the vibrational energy levels of CO and N<subscript>2</subscript> are treated as pseudo-species. The vibrational state-specific inelastic rate coefficients of N<subscript>2</subscript>–Ar collisions were calculated using the mixed quantum–classical method based on a newly developed three-dimensional potential energy surface. The StS predictions agreed well with the measurements, whereas deviations were found between the Schwartz–Slawsky–Herzfeld formula predictions and the measurements. The Millikan–White vibrational relaxation data of the N<subscript>2</subscript>–Ar system were found to have the most significant impact on the model predictions via sensitivity analysis. The vibrational relaxation data of the N<subscript>2</subscript>–Ar system were then modified according to the experimental data and StS results, providing an indirect way to optimize the vibrational relaxation data of a specific system. Moreover, the vibrational distribution functions of CO and N<subscript>2</subscript> and the effects of the vibration–vibration–translation energy transfer path on the thermal nonequilibrium behaviors were highlighted. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219606
- Volume :
- 160
- Issue :
- 22
- Database :
- Complementary Index
- Journal :
- Journal of Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 177896782
- Full Text :
- https://doi.org/10.1063/5.0212823