Published in Computational Mathematics and Mathematical Physics
AbstractA free axisymmetric nonswirling submerged jet of viscous incompressible fluid is considered. For large Reynolds numbers, the unknown constant in the asymptotic Landau–Rumer–Gol’dshtik–Yavorsky solution to the Navier–Stokes equations that describes the far jet field is determined. A similar constant in Loitsyanskii’s solution in the boundary...
Published in Computational Mathematics and Mathematical Physics
AbstractFor a mathematically correct formulation and analysis of the problems referred to in the title, a new approach, different from that previously used by specialists in fluid and gas mechanics, has been developed and justified. The main initial-boundary value problem for a third-order nonlinear ordinary differential equation on the entire real...
Published in Computational Mathematics and Mathematical Physics
AbstractOur aim in this paper is to present several generating functions for some classes of functions associated to the Fox–Wright functions. In particular, certain generating functions for a class of function involving the Fox–Wright functions will be expressed in terms of the H-function of two variables are investigated. As applications, some ge...
Published in Computational Mathematics and Mathematical Physics
AbstractThe problem of obtaining the form of a spatial supersonic nozzle cross section that intersects the circular critical cross section of the nozzle and an output circuit inscribed in the given dimensions, which has the greatest thrust among all possible admissible forms. is considered. The Lagrange functional, in which all gas-dynamics equatio...
Published in Computational Mathematics and Mathematical Physics
AbstractIt is well known that, under rather general conditions, the particle flux density in a multiplying medium is asymptotically exponential in time \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidem...
Published in Computational Mathematics and Mathematical Physics
AbstractHigh-accuracy numerical algorithms are proposed and justified for the simulation of cold plasma oscillations in both nonrelativistic and relativistic cases. A specific feature of the given approach is that Lagrangian variables are used for the approximate solution of the problem formulated in Eulerian variables. The main results are stated ...
Published in Computational Mathematics and Mathematical Physics
AbstractResults of a theoretical analysis of the convergence of geometric multigrid algorithms in solving linear boundary value problems on two-block grids are presented. The smoothing property for a nonsymmetric iterative method with parameter and the convergence of the robust multigrid technique are proved. It is shown that the number of multigri...
Published in Computational Mathematics and Mathematical Physics
AbstractProblems with inexactly specified parameters arise in many applications, and they are often formulated as dynamical systems with interval parameters. For such systems, it is required to know how to obtain an interval estimate of solution given the interval values of the parameters. The main idea underlying the adaptive interpolation algorit...
Published in Computational Mathematics and Mathematical Physics
AbstractA Cauchy problem for the kinetic and electrodynamic equations describing the self-consistent electromagnetic field of an electron beam propagating in a medium with discontinuous scattering properties and electrophysical characteristics is considered. An interpretation of the generalized solution as a particle method for the numerical soluti...
Published in Computational Mathematics and Mathematical Physics
AbstractTwo hyperbolic equations with a nonlinear coefficient multiplying the highest derivative are considered. The coefficient determines the velocity of nonlinear waves and characterizes the scattering properties of the medium. For stationary traveling-wave solutions, inverse problems are set up consisting of determining a nonlinear coefficient ...
