All issues

Статья представляет собой пример компьютерного моделирования в области инженерной механики. Численным методом находятся поля скорости в гидроциклоне, которые недоступны прямому измерению. Рассматривается численное моделирование трехмерной гидродинамики на основе k-ε RNG модели турбулентности в гидроциклоне со встроенным инжектором, содержащим 5 тангенциально направленных сопла. Показано, что направление движения инжектируемой жидкости зависит от расхода жидкости через инжектор. Расчеты показывают в соответствии с экспериментами, что зависимость сплит-параметра от расхода инжектируемой жидкости имеет немонотонный характер, связанный с отношением мощности основного потока и инжектируемой жидкости.

In this paper the problem of searching for the design of the magnetic system for creation a magnetic field with the required characteristics in the given area is solved. On the basis of analysis of the mathematical model of the magnetic system rather a general approach is proposed to the solving of the inverse problem, which is written by the Fredgolm equation H(z) = ∫_SIJ(s)G(z, s)ds, z ∈ S _H, s ∈ S _I . It was necessary to define the current density distribution function J(s) and the existing winding geometry for creation of a required magnetic field H(z). In the paper a method of solving those by means of regularized iterative processes is proposed. On the base of the concrete magnetic system we perform the numerical study of influence of different factors on the character of the magnetic field being designed.

The purpose of this paper is to generalize the macroscopic hydrodynamic vehicular traffic models by using the algorithm for constructing the adequate state equation — dependence the pressure from traffic density by taking into account the real experimental data (possibly using the parametric solutions for model equations). It is proved that this kind of state equation which closed model equations system and obtained from the experimentally observed form of the fundamental diagram — dependence the traffic intensity from its density, completely determines the all properties of the used phenomenological model.

Mathematical simulation on unsteady natural convection in a closed porous cylindrical cavity having finite thickness heat-conducting solid walls in conditions of convective heat exchange with an environment has been carried out. A boundary-value problem of mathematical physics formulated in dimensionless variables such as stream function and temperature on the basis of Darcy–Boussinesq model has been solved by finite difference method. Effect of a porous medium permeability 10^–5≤Da<∞, ratio between a solid wall thickness and the inner radius of a cylinder 0.1≤h/L≤0.3, a thermal conductivity ratio 1≤λ_1,2≤20 and a dimensionless time on both local distributions of isolines and isotherms and integral complexes reflecting an intensity of convective flow and heat transfer has been analyzed in detail.

Modification of the invariant imbedding method to describe the interaction of 3D electromagnetic field with “woodpile” photonic crystal of finite thickness is considered in this paper. This modification allows solving a problem of evanescent modes resonant amplification during numerical calculations for the first layer of photonic crystal. The mathematical model created in this work gives good agreement with physical experiment results.

We consider two versions of the maximum cross section method for the solutions of the stationary equation of radiative transfer in dimensional inhomogeneous medium. Both are based on the application Monte-Carlo method to the summation of the Neumann series for the solution transport equation. First modification is traditional and second is based on the use of branching Markov chains. We carried out numerical comparison of these algorithms.

The article contains results of modeling a meteor entering dense atmosphere layers using Galerkin’s method and smoother particle hydrodynamics. Numerical simulations were run using experimental data gathered for the Chelyabinsk meteor while varying the meteor material characteristics and its orientation when entering the atmosphere.

In this paper, we present new parallel algorithms for finite element analysis implemented in the FEStudio software framework. We describe the programming model of finite element method, which supports parallelism on different stages of numerical simulations. Using this model, we develop parallel algorithms of numerical integration for dynamic problems and local stiffness matrices. For constructing and solving the systems of equations, we use the CUDA programming platform.

A method and a complex of computer programs are developed for the numerical simulation of the polaron states excitation process in condensed media. A numerical study of the polaron states formation in water under the action of the ultraviolet range laser irradiation is carried out. Our approach allows to reproduce the experimental data of the hydrated electrons formation. A numerical scheme is presented for the solution of the respective system of nonlinear partial differential equations. Parallel implementation is based on the MPI technique. The numerical results are given in comparison with the experimental data and theoretical estimations.

The static three-level game-theoretic model of three-level control system of the ship’s water ballast is built. The methods of hierarchical control in view of requirements of keeping the system in the given state are used. A comparison of the results of study of the model in terms of $\Gamma_1$ and $\Gamma_2$ Germeyer’s games is conducted. Numerical calculations for some typical cases are given.