Scaled Boltzmann theory for k-dependent test particle correlation functions in moderately dense gases)

Journal Article · Sun Apr 15 04:00:00 EST 1979 · J. Chem. Phys.; (United States)

OSTI ID:6203594

Chen, S; Rahman, A

Applicability of the hard sphere Boltzmann--Lorentz--Enskog test particle kinetic equation to the study of self-diffusion in moderately dense gases is assessed by comparing the numerical solutions of the equation for the velocity autocorrelation function, the kinetic energy autocorrelation function and the k-dependent test particle position correlation function with data generated from computer molecular dynamics and also with an incoherent quasielastic neutron scattering experiment. In order to adapt the hard sphere theory to explain data generated from systems in which particles interact via continuous potentials, the following procedure has been tested: We fix the effective collision frequency in the hard sphere kinetic equation by using the experimentally measured value of the self-diffusion coefficient. The results of the comparison show that this ''scaled Boltzmann theory'' compares well with the data for a system with a purely repulsive potential up to fairly high densities; however, increasing deviations are noticeable for a system in which the attractive part of the potential is included. This is so, especially at lower temperatures.

• Research Organization: Nuclear Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 6203594
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 70:8; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

657006* -- Theoretical Physics-- Statistical Physics & Thermodynamics-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CORRELATION FUNCTIONS
DIFFUSION
EQUATIONS
FLUIDS
FUNCTIONS
GASES
KINETIC EQUATIONS
SELF-DIFFUSION
TEST PARTICLES