Vibrational relaxation times in polyatomic gas mixtures on the validity of the linear mixture rule

Abstract

The vibrational relaxation times in SO 2Ar and CH 4Ar mixtures have been estimated in the temperature range 300–2000 K. following the SSH-Tanczos method. The inverse relaxation times are found to be non-linear in concentration of the relaxing gas and the deviation from linearity is more pronounced at high temperatures. It is argued that the intramolecular vibration-vibration energy transfer is responsible for such non-linear dependence on concentration.