12 papers · 1 filter
Characterization of the near-null error components utilized in composite adaptive AMG solvers
Austen J. Nelson, Panayot S. Vassilevski
We provide a theoretical justification for the construction of adaptive composite solvers based on a sequence of AMG (algebraic multigrid) -cycle methods that exploit error comp…
Scalable Multilevel Monte Carlo Methods Exploiting Parallel Redistribution on Coarse Levels
Hillary R. Fairbanks, Delyan Z. Kalchev, Chak Shing Lee +1
We study an element agglomeration coarsening strategy that requires data redistribution at coarse levels when the number of coarse elements becomes smaller than the used computatio…
Multilevel well modeling in aggregation-based nonlinear multigrid for multiphase flow in porous media
Chak Shing Lee, François P. Hamon, Nicola Castelletto +2
A full approximation scheme (FAS) nonlinear multigrid solver for two-phase flow and transport problems driven by wells with multiple perforations is developed. It is an extension t…
An Aggregation-based Nonlinear Multigrid Solver for Two-phase Flow and Transport in Porous Media
Chak Shing Lee, François P. Hamon, Nicola Castelletto +2
A nonlinear multigrid solver for two-phase flow and transport in a mixed fractional-flow velocity-pressure-saturation formulation is proposed. The solver, which is under the framew…
Multilevel Hierarchical Decomposition of Finite Element White Noise with Application to Multilevel Markov Chain Monte Carlo
Hillary R. Fairbanks, Umberto Villa, Panayot S. Vassilevski
In this work we develop a new hierarchical multilevel approach to generate Gaussian random field realizations in an algorithmically scalable manner that is well-suited to incorpora…
Nonlinear multigrid based on local spectral coarsening for heterogeneous diffusion problems
Chak Shing Lee, François Hamon, Nicola Castelletto +2
This work develops a nonlinear multigrid method for diffusion problems discretized by cell-centered finite volume methods on general unstructured grids. The multigrid hierarchy is…