|
|
Large-scale geosimulations using GEM and trilions
Blaheta, Radim ; Jakl, Ondřej ; Hrtus, Rostislav ; Kolcun, Alexej ; Kohut, Roman ; Starý, Jiří ; Turan, E.
The project deals with efficient solution of singular symmetric positive semidefinite problems. Our motivation arises from the \nneed to solve special problems of geotechnics, e.g. to perform upscaling analysis of geocomposites. In that and other applications we have to solve boundary problems with pure Neumann boundary conditions. We show that the stabilised PCG method with various preconditioners is a good choice for systems resulting from the numerical solution of Neumann problems, or more generally problems with a known small dimensional null space. The work was also taken as an opportunity to compare parallel implementations of the orresponding solvers, namely implementations in the in-house finite element software GEM and implementations employing components of the general Trilinos library. The studies show that the solvers based on GEM are highly competitive with its recognised counterpart.
|
|
| |
|
|
Řešení úloh s čistými Neumannovými okrajovými podmínkami na vnější hranici
Kohut, Roman
The pure Neumann boundary value problem is solvable only if all the applied external forces are balanced which means that the resultants of all forces and their moments vanish. The disturbance of the condition of balanced forces causes divergence of the used iterative method. For obtaining some numerical results we must seek generalized solution and modify the numerical techniques.
|
|
|
Matematický model podzemního úložiště jaderných odpadů
Kohut, Roman
The paper concerns the mathematical modelling of thermo-mechanical processes in nuclear waste repositories. The aim of the contribution is to show the experience with the computing of a large practical problem concerning the assessment of the influence of the distance between the deposition places to the thermo-elastic response of the rock massif.
|
|
|
Modelování THM procesů v horninách
Blaheta, Radim ; Kohut, Roman ; Neytcheva, M. ; Starý, Jiří
This paper is devoted to medelling thermal (T), hydraulic (H) and mechanical (M) processes in rocks.These physical processes seem to be most important ones for many engineering applications ranging from the classical mining, tunelling and underground constructions to new geotechnologies of waste disposal or geothermal anergy utilization.
|
|
| |
|
| |
|
|
Paralelní počítání termoelastického modelu KBS
Starý, Jiří ; Kohut, Roman
The paper describes numerical experiments with a finite element solution of the thermo-elasticity model KBS. Especially, it is devoted to the parallel computing of nonstacionary heat conduction problem, when the linear systems arising in each time step are solved by the overlapping domain decomposition method.
|
|
|
Aplikace paralelních výpočtů v geotechnice
Starý, Jiří ; Blaheta, Radim ; Kohut, Roman
The paper concerns the mathematical modelling of elasticity and thermo-elasticity problems arising from two challenging geotechnical tasks. The modelling leads to solving the sequence of large-scale systems of linear equations. For such systems, we use high performance iterative solvers being able to run on parallel computers.
|
|
|
Solution of Nonstacionary Thermoelasticity Problems
Kohut, Roman
The paper deals with a finite element solution of transient thermoelasticity problems. For each time step the system of linear algebraic equations is solved using the conjugate gradient method preconditioned by incomplete factorization of the matrix derived from the original matrix. The time step is chosen adaptively. The results of numerical tests are presented.
|
guest ::
RSS feed.