Abstract
Using laser schlieren measurements of vibrational relaxation of CO
2
in mixtures with
3
He; with
4
He; with
n
-H
2
; with
p
-H
2
; with
n
-D
2
; with
o
-D
2
and with HD behind incident shock waves, we have obtained estimates of the rotational–vibration coupling rates (v. r.) between the bending mode of CO
2
and hydrogen. Agreement with calculations based on the model of Sharma is very good, but the unusually fast relaxation rates observed in CO
2
-HD mixtures argues for the importance of the rotational (r. t.) relaxation rate of the H
2
isomer, as well as the (v. r.) exchange rate. Indeed a consistent picture of the kinetics can be obtained only if the (r. t.) process is considered to be rate limiting in H
2
and D
2
mixtures, but not in HD mixtures. This is consistent with measurements of the rotational relaxation times of these molecules. On the basis of the results in HD–CO
2
mixtures we suggest that the first order model of Sharma underestimates the coupling rate by a factor of 2, a result supported by independent ultrasonics and impact tube measurements on the CO
2
–H
2
system. We do not consider this discrepancy between experiment and theory to be significant.
Reference11 articles.
1. Ghem. P hys;Lett.,1971
2. J . diem;Dillon T. A.;Phys.,1973
3. Cross R . J . & Gordon R . G. 1966 J . chem. P hys. 45 3571.
4. Herzberg G. 1945 Infrared and R am an spectra. New Y ork: Van N ostrand.
5. Hirschfelder J . O. Curtiss C. F . & Bird R . B. 1954 Molecular theory of gases and liquids. New Y ork: W iley.
Cited by
9 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献