Про визначення області частотної дисперсії коефіцієнтів перенесення класичних рідин залежно від природи затухання релаксуючих потоків

• Main Author: Odinaev, S.
• Format: Article
• Language: English
• Published: Publishing house "Academperiodika" 2022
• Subjects: -
• Online Access: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2022037

We consider the frequency dispersion region of the dynamic shear viscosity coefficient ηs (ω) of simple liquids obtained by the method of kinetic equations, where the equilibrium structure of a liquid is restored according to the diffusion law or exponentially. At a certain choice of the intermolecular interaction potential Φ (|r|) and the equilibrium radial distribution function g0 (|r|), the coefficient ηs (ω) for liquid argon was numerically calculated as a function of the density ρ, temperature T, and frequency ω. The obtained theoretical values of the shear viscosity ηs (ω) are in a satisfactory quantitative agreement with experimental data. It is shown that the frequency dispersion region of ηs (ω) obtained on the basis of the diffusive mechanism, i.e. structural relaxation, is large (~ 105 Hz). In the case of the exponential attenuation of the viscous stress tensor, this region is narrow (~ 102 Hz), which agrees both with acoustic measurements and the results of a phenomenological theory.