A flux-free a posteriori error estimator for the incompressible Stokes problem using a mixed FE formulation
In this contribution, we present an a posteriori error estimator for the incompressible Stokes problem valid for a conventional mixed FE formulation. Due to the saddle-point property of the problem, conventional error estimators developed for pure minimization problems cannot be utilized straight-fo...
| Autores: | , , |
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| Formato: | artículo |
| Fecha de publicación: | 2010 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/10309 |
| Acesso em linha: | https://hdl.handle.net/2117/10309 https://dx.doi.org/10.1016/j.cma.2010.03.011 |
| Access Level: | acceso abierto |
| Palavra-chave: | Finite element method Error functions Numerical analysis Navier-Stokes equations Elements finits, Mètode dels Anàlisi numèrica Equacions de Navier-Stokes Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi numèrica::Mètodes en elements finits |
| Resumo: | In this contribution, we present an a posteriori error estimator for the incompressible Stokes problem valid for a conventional mixed FE formulation. Due to the saddle-point property of the problem, conventional error estimators developed for pure minimization problems cannot be utilized straight-forwardly. The new estimator is built up by two key ingredients. At first, a computed error approximation, exactly fulfilling the continuity equation for the error, is obtained via local Dirichlet problems. Secondly, we adopt the approach of solving local equilibrated flux-free problems in order to bound the remaining, incompressible, error. In this manner, guaranteed upper and lower bounds, of the velocity “energy norm” of the error as well as goaloriented (linear) output functionals, with respect to a reference (overkill) mesh are obtained. In particular, it should be noted that this approach requires no computation of hybrid fluxes. Furthermore, the estimator is applicable to mixed FE formulations using continuous pressure approximations, such as the Mini and Taylor– Hood class of elements. In conclusion, a few simple numerical examples are presented, illustrating the accuracy of the error bounds. |
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