463
eng
reportzib
0
1989-11-03
1989-11-03
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Adaptive multilevel discretization in time and space for parabolic partial differential equations.
The present paper developes an adaptive multilevel approach for parabolic PDE's - as a first step, for one linear scalar equation. Full adaptivity of the algorithm is conceptually realized by simultaneous multilevel discretization in both time and space. Thus the approach combines multilevel time discretization, better known as extrapolation methods, and multilevel finite element space discretization such as the hierarchical basis method. The algorithmic approach is theoretically backed by careful application of fundamental results from semigroup theory. These results help to establish the existence of asymptotic expansions (in terms of time-steps) in Hilbert space. Finite element approximation then leads to perturbed expansions, whose perturbations, however, can be pushed below a necessary level by means of an adaptive grid control. The arising space grids are not required to satisfy any quasi- uniformity assumption. Even though the theoretical presentation is independent of space dimension details of the algorithm and numerical examples are given for the 1-D case only. For the 1-D elliptic solver, which is used, an error estimator is established, which works uniformly well for a family of elliptic problems. The numerical results clearly show the significant perspectives opened by the new algorithmic approach.
TR-89-07
463
urn:nbn:de:0297-zib-4638
Folkmar A. Bornemann
ZIB-Report
TR-89-07
Informatik, Informationswissenschaft, allgemeine Werke
ZIB Allgemein
https://opus4.kobv.de/opus4-zib/files/463/TR-89-07.pdf