Prof. Miloslav Feistauer seventieth birthday celebration
Anisotropic -adaptive method based on interpolation error estimates in the -seminorm
We develop a new technique which, for the given smooth function, generates the anisotropic triangular grid and the corresponding polynomial approximation degrees based on the minimization of the interpolation error in the broken -seminorm. This technique can be employed for the numerical solution of boundary value problems with the aid of finite element methods. We present the theoretical background of this approach and show several numerical examples demonstrating the efficiency of the proposed...
On the solution of linear algebraic systems arising from the semi–implicit DGFE discretization of the compressible Navier–Stokes equations
We deal with the numerical simulation of a motion of viscous compressible fluids. We discretize the governing Navier–Stokes equations by the backward difference formula – discontinuous Galerkin finite element (BDF-DGFE) method, which exhibits a sufficiently stable, efficient and accurate numerical scheme. The BDF-DGFE method requires a solution of one linear algebra system at each time step. In this paper, we deal with these linear algebra systems with the aid of an iterative solver. We discuss...
Impaktní faktory matematických časopisů v roce 2008
Goal-oriented error estimates including algebraic errors in discontinuous Galerkin discretizations of linear boundary value problems
We deal with a posteriori error control of discontinuous Galerkin approximations for linear boundary value problems. The computational error is estimated in the framework of the Dual Weighted Residual method (DWR) for goal-oriented error estimation which requires to solve an additional (adjoint) problem. We focus on the control of the algebraic errors arising from iterative solutions of algebraic systems corresponding to both the primal and adjoint problems. Moreover, we present two different reconstruction...
Prof. Miloslav Feistauer seventy-fifth birthday celebration
Výpočtová matematika a počítačová dynamika tekutin
Discontinuous Galerkin method for nonlinear convection-diffusion problems with mixed Dirichlet-Neumann boundary conditions
The paper is devoted to the analysis of the discontinuous Galerkin finite element method (DGFEM) applied to the space semidiscretization of a nonlinear nonstationary convection-diffusion problem with mixed Dirichlet-Neumann boundary conditions. General nonconforming meshes are used and the NIPG, IIPG and SIPG versions of the discretization of diffusion terms are considered. The main attention is paid to the impact of the Neumann boundary condition prescribed on a part of the boundary on the truncation...
On discontinuous Galerkin methods for nonlinear convection-diffusion problems and compressible flow
The paper is concerned with the discontinuous Galerkin finite element method for the numerical solution of nonlinear conservation laws and nonlinear convection-diffusion problems with emphasis on applications to the simulation of compressible flows. We discuss two versions of this method: (a) Finite volume discontinuous Galerkin method, which is a generalization of the combined finite volume—finite element method. Its advantage is the use of only one mesh (in contrast to the combined finite volume—finite...
Special issue dedicated to Professor Ivo Babuška, the founder of the journal Applications of Mathematics
-anisotropic mesh adaptation technique based on interpolation error estimates
We present a completely new -anisotropic mesh adaptation technique for the numerical solution of partial differential equations with the aid of a discontinuous piecewise polynomial approximation. This approach generates general anisotropic triangular grids and the corresponding degrees of polynomial approximation based on the minimization of the interpolation error. We develop the theoretical background of this approach and present a numerical example demonstrating the efficiency of this anisotropic...
An adaptive -discontinuous Galerkin approach for nonlinear convection-diffusion problems
We deal with a numerical solution of nonlinear convection-diffusion equations with the aid of the discontinuous Galerkin method (DGM). We propose a new -adaptation technique, which is based on a combination of a residuum estimator and a regularity indicator. The residuum estimator as well as the regularity indicator are easily evaluated quantities without the necessity to solve any local problem and/or any reconstruction of the approximate solution. The performance of the proposed -DGM is demonstrated....
An efficient implementation of the semi-implicit discontinuous Galerkin method for compressible flow simulation
We deal with a numerical simulation of the inviscid compressible flow with the aid of the combination of the discontinuous Galerkin method (DGM) and backward difference formulae. We recall the mentioned numerical scheme and discuss implementation aspects of DGM, particularly a choice of basis functions and numerical quadratures for integrations. An illustrative numerical example is presented.
Error estimates for barycentric finite volumes combined with nonconforming finite elements applied to nonlinear convection-diffusion problems
The subject of the paper is the derivation of error estimates for the combined finite volume-finite element method used for the numerical solution of nonstationary nonlinear convection-diffusion problems. Here we analyze the combination of barycentric finite volumes associated with sides of triangulation with the piecewise linear nonconforming Crouzeix-Raviart finite elements. Under some assumptions on the regularity of the exact solution, the and error estimates are established. At the end...
Analysis of a combined barycentric finite volume—nonconforming finite element method for nonlinear convection-diffusion problems
We present the convergence analysis of an efficient numerical method for the solution of an initial-boundary value problem for a scalar nonlinear conservation law equation with a diffusion term. Nonlinear convective terms are approximated with the aid of a monotone finite volume scheme considered over the finite volume barycentric mesh, whereas the diffusion term is discretized by piecewise linear nonconforming triangular finite elements. Under the assumption that the triangulations are of weakly...
Analysis of the discontinuous Galerkin finite element method applied to a scalar nonlinear convection-diffusion equation
We deal with a scalar nonstationary convection-diffusion equation with nonlinear convective as well as diffusive terms which represents a model problem for the solution of the system of the compressible Navier-Stokes equations describing a motion of viscous compressible fluids. We present a discretization of this model equation by the discontinuous Galerkin finite element method. Moreover, under some assumptions on the nonlinear terms, domain partitions and the regularity of the exact solution,...
Discontinuous Galerkin method for compressible flow and conservation laws
This paper is concerned with the application of the discontinuous Galerkin finite element method to the numerical solution of the compressible Navier-Stokes equations. The attention is paid to the derivation of discontinuous Galerkin finite element schemes and to the investigation of the accuracy of the symmetric as well as nonsymmetric discretization.
Goal oriented a posteriori error estimates for the discontinuous Galerkin method
This paper is concerned with goal-oriented a posteriori error estimates for discontinous Galerkin discretizations of linear elliptic boundary value problems. Our approach combines the Dual Weighted Residual method (DWR) with local weighted least-squares reconstruction of the discrete solution. This technique is used not only for controlling the discretization error, but also to track the influence of the algebraic errors. We illustrate the performance of the proposed method by numerical experiments....
Solution of time-dependent convection-diffusion equations with the aid of higher order adaptive methods with respect to space and time
Discontinuous Galerkin method for the simulation of 3D viscous compressible flows
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