Kinetic equations for dense gases and liquids

On the problem of a consistent description of kinetic and hydrodynamic processes in dense gases and liquids

“…Their role is especially important at high densities, when the interaction between a separate group of particles and other ones cannot be neglected. This indicates a close connection between the kinetic and hydrodynamic processes in dense gases and liquids [3,4]. Therefore, to obtain the kinetic equations for these systems it is quite natural to choose the reduced description of nonequilibrium states and in such a way to automatically take into account a proper dynamics of conserved quantities.…”

“…An important common problem of these investigations consists in the calculation of the generalized transport kernels (memory functions). The latter determine the collision integrals for various models [1,[13][14][15][16][17][18][19][20][21][22][23][24] as well as the generalized transport coefficients such as viscosity and heat conductivity [1,3,4]. This problem is particularly significant in the region of short-ranged interactions.…”

“…A regular perturbation theory can be implemented for solving such an equation. Using the ideas of paper [3,4] the generalized transport equations for the hydrodynamic variables such as number of particles, momentum and total energy densities were obtained in [7,9] by means of nonequilibrium statistical operator method. Such equations are consistent with the kinetic equation for the nonequilibrium one-particle distribution function.…”

“…A number of investigations [1][2][3][4][5][6][7][8][9][10][11][12] was devoted to the problem of constructing a consistent description of kinetic and hydrodynamic processes in dense gases, liquids, and plasma. The paper by D.N.…”

A collision term valid from rarefied to dense gases and plasmas

“…Its importance has been stressed in the last four decades (Frieman and Book 1963;Montgomery and Tidman 1964;Liboff 1969;Chapman and Cowling 1970;van Beyeren and Ernst 1979;Klimontovich 1982;Zubarev et al 1991;Xing 1998) and is estimated by either of the ratios τ = t c /t m , χ= σ/l m where t c is the time spent within the field effect of the target, σ is the radius of the cross section for interaction, l m and t m the mean free path and mean collision time. When τ Ӷ 1 and χ Ӷ 1, the Boltzmann collision term is valid; otherwise, correlation aspects must be considered.…”