hp-FEM for the α-Mosolov problem

a priori and a posteriori error estimates

authored by
Lothar Banz, Ernst P. Stephan
Abstract

An hp-finite element discretization for the α-Mosolov problem, a scalar variant of the Bingham flow problem but with the α-Laplacian operator, is being analyzed. Its weak formulation is either a variational inequality of second kind or equivalently a non-smooth but convex minimization problem. For any α∈(1,∞) we prove convergence, including guaranteed convergence rates in the mesh size h and polynomial degree p of the FE-solution of the corresponding discrete variational inequality. Moreover, we derive two families of reliable a posteriori error estimators which are applicable to any “approximation” of the exact solution and not only to the FE-solution and can therefore be coupled with an iterative solver. We prove that any quasi-minimizer of those families of a posteriori error estimators satisfies an efficiency estimate. All our results contain known results for the Mosolov problem by setting α=2. Numerical results underline our theoretical findings.

Organisation(s)
Institute of Applied Mathematics
External Organisation(s)
University of Salzburg
Type
Article
Journal
Numerische Mathematik
Volume
156
Pages
1679-1718
No. of pages
40
ISSN
0029-599X
Publication date
10.2024
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Computational Mathematics, Applied Mathematics
Electronic version(s)
https://doi.org/10.1007/s00211-024-01433-8 (Access: Open)