A spectral element solution of the Poisson equation with shifted boundary polynomial corrections: influence of the surrogate to true boundary mapping and an asymptotically preserving Robin formulation
ENGSIG-KARUP, Allan Peter
Department of Applied Mathematics and Computer Science [Lyngby] [DTU Compute]
Department of Applied Mathematics and Computer Science [Lyngby] [DTU Compute]
RICCHIUTO, Mario
Certified Adaptive discRete moDels for robust simulAtions of CoMplex flOws with Moving fronts [CARDAMOM]
Certified Adaptive discRete moDels for robust simulAtions of CoMplex flOws with Moving fronts [CARDAMOM]
ENGSIG-KARUP, Allan Peter
Department of Applied Mathematics and Computer Science [Lyngby] [DTU Compute]
Department of Applied Mathematics and Computer Science [Lyngby] [DTU Compute]
RICCHIUTO, Mario
Certified Adaptive discRete moDels for robust simulAtions of CoMplex flOws with Moving fronts [CARDAMOM]
< Réduire
Certified Adaptive discRete moDels for robust simulAtions of CoMplex flOws with Moving fronts [CARDAMOM]
Langue
en
Document de travail - Pré-publication
Ce document a été publié dans
2023
Résumé en anglais
We present a new high-order accurate spectral element solution to the two-dimensional scalar Poisson equation subject to a general Robin boundary condition. The solution is based on a simplified version of the shifted ...Lire la suite >
We present a new high-order accurate spectral element solution to the two-dimensional scalar Poisson equation subject to a general Robin boundary condition. The solution is based on a simplified version of the shifted boundary method employing a continuous arbitrary order $hp$-Galerkin spectral element method as the numerical discretization procedure. The simplification relies on a polynomial correction to avoid explicitly evaluating high-order partial derivatives from the Taylor series expansion, which traditionally have been used within the shifted boundary method. In this setting, we apply an extrapolation and novel interpolation approach to project the basis functions from the true domain onto the approximate surrogate domain. The resulting solution provides a method that naturally incorporates curved geometrical features of the domain, overcomes complex and cumbersome mesh generation, and avoids problems with small-cut-cells. Dirichlet, Neumann, and general Robin boundary conditions are enforced weakly through: i) a generalized Nitsche's method and ii) a generalized Aubin's method. For this, a consistent asymptotic preserving formulation of the embedded Robin formulations is presented. We present several numerical experiments and analysis of the algorithmic properties of the different weak formulations. With this, we include convergence studies under polynomial, $p$, increase of the basis functions, mesh, $h$, refinement, and matrix conditioning to highlight the spectral and algebraic convergence features, respectively. This is done to assess the influence of errors across variational formulations, polynomial order, mesh size, and mappings between the true and surrogate boundaries.< Réduire
Mots clés en anglais
Numerical Analysis (math.NA)
FOS: Mathematics
Spectral element method
shifted boundary method
high-order numerical method
embedded methods
Poisson problem
elliptic problem
Dirichlet
Neumann
and Robin boundary conditions
Origine
Importé de halUnités de recherche