Title Information
Title
Finite Element Methods for Interface Problems Using Unfitted Meshes: Design and Analysis
Name: Personal
Name Part
Sanchez, Manuel A
Role
Role Term: Text
creator
Origin Information
Copyright Date
2016
Physical Description
Extent
xix, 179 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2016)
Name: Personal
Name Part
Guzman, Johnny
Role
Role Term: Text
Director
Name: Personal
Name Part
Ainsworth, Mark
Role
Role Term: Text
Reader
Name: Personal
Name Part
Sarkis, Marcus
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Applied Mathematics
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
This dissertation aims to study finite element methods for two-dimensional stationary second order interface model problems on homogeneous and heterogeneous media, under discretizations non-fitted with the interface. We propose novel numerical methods for the model interface problems, proving optimal convergence of the errors and robust error estimates with respect to the curvature of the interface and the physical parameters of the problems. In the first part of the dissertation, we consider the Poisson and Stokes interface problems on homogeneous media. In both cases, we design correction terms relying on the interface jump conditions of the problem for each unknown variable, which are then added to the right-hand side of the system. This technique is developed for arbitrary polynomial order of the finite element subspace, by means of higher order derivative jumps of the solution derived from the problem. We provide pointwise error analyses of the methods obtaining optimal convergence of the errors. The second part assesses the classical elliptic interface model problem on heterogeneous media: Poisson equations with discontinuous constant coefficients. In particular, we examine the case in which the contrast of the diffusion coefficients is high. We present an a priori analysis of the regularity in order to develop error estimates for the numerical methods consistent with the behavior of the solution. Furthermore, we propose and analyze two finite element methods, following distinct approaches, for the high contrast Poisson interface problem. The first method follows the philosophy of Immersed Finite Element methods, incorporating the jump conditions of the problem strongly in the finite element subspace. Optimal error estimates independent of the contrast of the diffusion coefficients are proved. A detailed analysis incorporating the curvature of the interface and the regularity of the solution is presented, guaranteeing robustness of the method. The second numerical approximation is based on a Nitsche finite element method, with flux stabilization terms. This approach imposes the jumps conditions of the problem weakly, in the form of penalty terms with support on the interface that are added to the system. Optimal error estimates independent of the high-contrast are demonstrated, including a novel error estimate for the flux of the solution. Finally, numerical evidence of the properties of the finite element approximations are displayed for each problem, corroborating the theoretical findings.
Subject
Topic
interface problems
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/924897")
Topic
Finite element method
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20160629
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0JD4V58
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations