|
|
Numerical simulation of compressible flows with the aid of multigrid methods
Živčák, Andrej ; Dolejší, Vít (advisor) ; Knobloch, Petr (referee)
We deal with the numerical solution of the Navier-Stokes equations describing a motion of viscous compressible flows. The governing equations are discretized with the aid of discontinuous Galerkin finite element method which is based on a discontinuous piecewise polynomial approximation. The discretizations leads to a large nonlinear algebraic system. In order to solve this system efficiently, we develop the so-called p-multigrid solution strategy which employ as a projec- tion and a restriction operators the L2 -projection in the spaces of polynomial functions on each element separately. The p-multigrid technique is studied, deve- loped and implemented in the code ADGFEM. The computational performance of the method is presented.
|
|
|
Multilevel methods and adaptivity
Vacek, Petr ; Strakoš, Zdeněk (advisor) ; Tichý, Petr (referee)
After introduction of the model problem we derive its weak formulation, show the existence and the uniqueness of the solution, and present the Galerkin finite element method. Then we briefly describe some of the stationary iterative methods and their smoothing property. We present the most common multigrid schemes, i.e. two-grid correction scheme, V-cycle scheme, and the full multigrid algorithm. Then we perform numerical experiment showing the differences between the use of the direct and iterative coarsest grid solver in V-cycle scheme and experiment considering a perturbation of the correction vector simulating a fault of a computational device. Powered by TCPDF (www.tcpdf.org)
|
|
|
Numerical simulation of compressible flows with the aid of multigrid methods
Živčák, Andrej ; Dolejší, Vít (advisor) ; Knobloch, Petr (referee)
We deal with the numerical solution of the Navier-Stokes equations describing a motion of viscous compressible flows. The governing equations are discretized with the aid of discontinuous Galerkin finite element method which is based on a discontinuous piecewise polynomial approximation. The discretizations leads to a large nonlinear algebraic system. In order to solve this system efficiently, we develop the so-called p-multigrid solution strategy which employ as a projec- tion and a restriction operators the L2 -projection in the spaces of polynomial functions on each element separately. The p-multigrid technique is studied, deve- loped and implemented in the code ADGFEM. The computational performance of the method is presented.
|
|
|
FEM solver for incompressible flow problems
Bauer, Petr ; Klement, V. ; Žabka, V.
We develop a FEM solver for flow problems based on incompressible Navier-Stokes equations. The discretization of the convective term is semi-implicit and the resulting linear systems are solved using multigrid techniques. The parallel implementations via OpenMP and NVidia CUDA are presented and their performance is compared.
|
guest ::
