1,721,078 research outputs found
Molecular dynamics and Enskog theory calculation of one dimensional problems in the dynamics of dense gases
No full textThe Enskog equation is solved by a numerical method which combines finite difference discretization with Monte Carlo quadrature techniques for the evaluation of the collision integral. The method is applied to the study of two one-dimensional problems in the kinetic theory of a dense hard sphere gas. The Enskog theory solutions are also compared with molecular dynamics simulations
Numerical study of the strong evaporation of a binary mixture
No full textThe problem of the one-dimensional evaporation of a binary mixture is investigated by numerically solving a system of two coupled Boltzmann equations. The numerical method is based on the direct discretization of the Boltzmann equation and the Monte Carlo evaluation of the collision integrals. It is assumed that the fluid flows between an evaporating plate and a totally absorbing plate. The spatial profiles of macroscopic quantities as well as evaporation rates have been calculated for values of the Knudsen number between 1 2 and 1 20. © 1991
A numerical investigation of the steady evaporation of a polyatomic gas
No full textThe evaporation and condensation of a polyatomic vapor in contact with its condensed phase has received much less attention
than the monatomic case. In this paper we investigate the structure of the Knudsen layer formed in the steady evaporation of a
vapor whose molecules behave as rigid rotators. The vapor motion is obtained by the numerical solution of the Boltzmann equation
by the Direct Simulation Monte Carlo (DSMC) method. The obtained results are also compared with the solutions of a simplified
kinetic BGK-like model equation. It is shown that density and temperature drops across the Knudsen layer are reasonably well
reproduced by approximate methods proposed in the literature
The propagation of infinitesimal disturbances in an ultrarelativistic gas according to the method of elementary solutions
No full textIt has recently been shown that a linearized relativistic BGK model can be reduced, in the ultrarelativistic limit, to a system of three uncoupled transport equations for thermal, sound, and shear waves. The equation describing the propagation of thermal waves is the well-known one-speed neutron transport with isotropic scattering in the conservative case. In this paper the solution of the half-space problem for the equation describing the propagation of shear and sound waves is given according to Case's elementary solutions method. © 1987 Plenum Publishing Corporation
Kinetic theory aspects of non-equilibrium liquid-vapor flows
Full text linkKinetic theory of fluids plays an important role in understanding and modeling mass, momentum and energy
transfer between the vapor and liquid phase in non-equilibrium two-phase flows, in which evaporation and/or
condensation take place. The paper presents a review of the literature which focuses on kinetic modeling of the
vapor-liquid interface. Starting from the studies of the Knudsen layer structure in evaporation and condensation, the
problem of the formulation of kinetic boundary conditions is described and discussed. The formulation of models
based on approximate kinetic descriptions of dense fluids is described and the model capabilities are assessed
through the analysis of the results obtained by various author
A particle scheme for the numerical solution of the Enskog equation
No full textIt is shown that the kinetic equation proposed by Enskog for a dense hard sphere gas can be solved numerically by a particle simulation method. The technique can be extension of the well known DSMC method used to solve the Boltzmann euation. Unlike a recently proposed Nanbu-like particle scheme, the present method exactly preserves momentum and energy. The calculation of the density profile in a dense gas in equilibrium near a hard wall is presented as an example. © 1997 American Institute of Physics
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