Vibrational‐rotational energy transfer in mixtures of nitrogen and water vapor

Abstract

The following de‐excitation rates have been computed according to the theoretical treatments of Shin [J. Chem. Phys. 60, 1064–1070 (1974)], and Nagel and Rogovin [J. Chem. Phys. 72, 6593–6601 (1980)] for N2−H2O mixtures: k20. de‐excitation of N2 by H2O (VT); k30, near‐resonant transfer (VVR); and k50, de‐excitation of H2O by N2(VT). At 300°K the theoretical values are respectively 0.11, 1.76 × 105, and 3.1 × 104, as compared with the experimental values of <3 × 104, 1.25 × 1O5, and 4.6 × 104, all in (atm⋅s)−1, obtained acoustically in a resonant tube. These results demonstrate the dominance of VVR over VT transfer in the N2−H2O system, and support the conclusion of Nagel and Rogovin that the large rate k30 is “due to the vast number of VR modes H2O has available to absorb energy.”