Search

The Boltzmann equation is a complex integral-differential equation and the basis of the kinetic theory of gases. It describes the behavior of a rarefied gas in space of time and velocity. It is used to the study of electron transport in solids and plasmas, neutron transport in nuclear reactors, in the tasks of remote sensing of the Earth from Space. The moment method is one of effective methods for solution of the Boltzmann equation. The system of Boltzmann’s moment equations is intermediate between kinetic and hydrodynamic levels of description of state of the rarefied gas and form class of nonlinear partial differential equations. If particle distribution function will be decomposed into an Fourier series on complete orthogonal system of functions, then Boltzmann’s equation will be equivalent to an infinite system of partial differential equations relative to the moments of the particle distribution function in the complete system of eigenfunctions of linearized operator. But solving infinite system of differential equations impossible. Therefore, an approximate solution of the initial and boundary value problem for the Boltzmann equation can be determined by the moment method. This article describes the one-dimensional nonlinear nonstationary Boltzmann’s moment system equations in the third approximation, which a hyperbolic system of partial differential equations and contains six equations for the moments of the particle distribution function. And formulates the statement of the initial and boundary value problem for the Boltzmann’s moment system equations in the third approximation and shows the results of the numerical solution with the Vladimirov-Marshak boundary conditions.