Simple model for describing the density dependence of the vibrational relaxation in a polyatomic nonassociated fluid

Journal Article · Sat Dec 01 04:00:00 EST 1979 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.438205· OSTI ID:5938762

Sedlacek, M; Asenbaum, A

A model is presented which allows the description of the density dependence of the vibrational relaxation in a fluid consisting of polyatomic molecules over a wide range of densities. In order to calculate the number of intermolecular collisions a molecule undergoes per unit time, use is made of the radial distribution function for a system of Lennard-Jones molecules as follows from molecular dynamics computer experiments. A density dependent energy exchange probability is introduced which partially compensates the influence of the steep increase in the intermolecular collision rate on the vibrational relaxation frequency above 350 amagats. Thus satisfactory agreement between theory and experiment can for instance be obtained between 0 and 600 amagats for CO/sub 2/ at 25 and 50 /sup 0/C.

• Research Organization: Institut fuer Experimentalphysik der Universitaet Wien, Strudlhofgasse 4, A 1090 Wien, Austria
• OSTI ID: 5938762
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 71:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
COLLISIONS
DENSITY
ENERGY LEVELS
EXCITED STATES
FLUIDS
MATHEMATICAL MODELS
MOLECULE COLLISIONS
MOLECULE-MOLECULE COLLISIONS
MOLECULES
PHYSICAL PROPERTIES
POLYATOMIC MOLECULES
RELAXATION
VIBRATIONAL STATES