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University of Illinois at Urbana-Champaign

Discontinuous differential equations

Abstract

dc:description

This thesis covers numerical methods for discontinuous differential equations. In the context of ordinary differential equations, we introduce conservative integrators for long term integration of piecewise smooth systems with transversal dynamics and piecewise smooth conserved quantities. In essence, for a piecewise dynamical system with piecewise defined conserved quantities such that its trajectories cross transversally to its interface, we combine Mannshardt's transition scheme and the Discrete Multiplier Method to obtain conservative integrators capable of preserving conserved quantities up to machine precision and accuracy order. We prove that the order of accuracy of the conservative integrators is preserved after crossing the interface in the case of codimension one number of conserved quantities. Numerical examples illustrate the preservation of accuracy order and conserved quantities across the interface. In the context of partial differential equations we introduce a numerical method based on discrete exterior calculus for the phase field equation. We prove the phase field variable remains bounded and satisfies mass conservation. Further, our method works on embedded two-dimensional Delaunay meshes in \mathbb{R}3. Numerical examples on an embedded cylinder in \mathbb{R}3 demonstrate both boundedness and mass conservation up to machine precision.

Degree

thesis:*
Name thesis:degree_name
Ph.D.
Level thesis:degree_level
Dissertation
Discipline thesis:degree_discipline
Mathematics
Grantor
University of Illinois at Urbana-Champaign
Year dc:date
2022

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Wojtalewicz, Nikolas
Contributors dc:contributor
  • Hirani, Anil
  • Wan, Andy
  • DeVille, Lee
  • Laugesen, Richard

Subjects

dc:subject × 4

Rights

dc:rights
Statement dc:rights
  • Copyright 2022 Nikolas Wojtalewicz
Language dc:language
en, eng

Identifiers

dc:identifier.*
Handle dc:identifier
https://hdl.handle.net/2142/116225

Chain of custody

source
Harvested from
University of Illinois - Urbana-Champaign
Base URL
www.ideals.illinois.edu/oai-pmh
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Wojtalewicz, Nikolas. Discontinuous differential equations. Dissertation thesis, University of Illinois at Urbana-Champaign, 2022. https://hdl.handle.net/2142/116225