Vibrational and rotational relaxation in mixtures of water vapor and oxygen

Experimental measurements of sound absorption in air, measurements of ultrasonic absorption in H2O/O2 mixtures at 500 °K reported here, and experimental measurements in mixtures of H2O with other impurities have been analyzed to determine the energy transfer rates in mixtures of O2 and H2O as a function of temperature. A set of energy transfer rate coefficients was found that give results consistent with all the experimental data examined and with vibrational energy transfer theory. The rotational relaxation time for H2O/O2 mixtures was determined from the 500 °K ultrasonic measurements. Subject Classification: [43]35.20, [43]35.35.