Research Colloquium
Thursday, November 13, 2008
"Advances in Wave Propagation with the Discontinuous Galerkin Method"
Tim
Warburton
Department of Computational and Applied Mathematics
Rice University
A range of important features relating to the practical application of
discontinuous Galerkin (DG) method for wave propagation will be discussed.
Recent investigations of the spectral properties of the discrete
discontinuous Galerkin operators have revealed important connections
with their continuous Galerkin counter parts. Theoretical and
numerical results will be shown which demonstrate the correct
asymptotic behavior of these methods and controls spurious solutions
under mild assumptions.
Given the suitability of DG for solving Maxwell's equations and their
ability to propagate waves over long distance, it is natural to seek
effective boundary treatments for artificial radiation boundary
conditions. A new family of far field boundary conditions will be
introduced which gracefully transmit propagating and evanescent
components out of the domain. These conditions are specifically
formulated with DG discretizations in mind, however they are also
relevant for a range of numerical methods.
There is an Achilles heel to high order discontinuous Galerkin methods
when applied to conservation laws. The methods are typically
constructed with polynomial field representations and unfortunately
these suffer from excess maximum gradients near the edges of elements.
I will describe a simple filtering process that allows us to reduce these
anomalous gradients and provably yield a dramatic increase in the
maximum allowable time step.
Finally, I will discuss the use of GPU hardware to accelerate computation
for time-domain electromagnetics simulations.
| Room: |
126 Clements Hall |
| Coffee: |
3:30 pm 3:45 pm |
| Colloquium: |
3:45 pm 4:45 pm |