Implementation of an implicit-explicit scheme for hybridizable discontinuous Galerkin

Abstract

Finite element methods, specifically Hybridizable Discontinuous Galerkin (HDG), are used in many applications. One choice made when implementing HDG for a specific problem is whether time integration should be performed implicitly or explicitly. Both approaches have their advantages but, for some problems, a combination of these methods is a better choice than either on their own. Thus, an implicit-explicit (IMEX) scheme that splits the computational domain into implicit and explicit regions based on the domain geometry is considered in this thesis. This allows for stability throughout the domain and exploits the advantages each scheme has to offer. A study of the convergence and properties of this implementation of the IMEX method is presented along with comparisons to the individual methods.