Nonlinear multilevel iterative methods for ...

Object Details

View

XVI International Conference on Computational Methods in Water Resources (CMWR-XVI) Ingeniørhuset

Nonlinear multilevel iterative methods for multiscale models of air/water flow in porous media
Paper
Author:Chris Kees <christopher.e.kees@erdc.usace.army.mil> (U.S. Army Engineer R&D Center)
Matthew Farthing <matthew_farthing@unc.edu> (University of North Carolina at Chapel Hill)
Lea Jenkins <lea@clemson.edu> (Clemson University)
C. T. Kelley <tim_kelley@ncsu.edu> (North Carolina State University)
Stacy Howington <stacy.e.howington@erdc.usace.army.mil> (U.S. Army Engineer R&D Center)
Presenter:Chris Kees <christopher.e.kees@erdc.usace.army.mil> (U.S. Army Engineer R&D Center)
Date: 2006-06-18     Track: Special Sessions     Session: Multiscale methods for flow in porous media
DOI:10.4122/1.1000000348
DOI:10.4122/1.1000000349

Richards' equation and the two-phase flow equations are well-known degenerate parabolic models of air/water flow in porous media. Poor iterative solver performance and small time steps during transient simulations are often reported in field-scale simulations. In this work we study Newton-multigrid and nonlinear multigrid methods applied to discrete air/water flow models. The models are discretized using standard continuous finite element spaces. Due to strong nonlinearity and potential degeneracy in the coefficients, we stabilize the models using a multiscale approach. We present computational results comparing iterative solver perfomance and solution accuracy, focusing particularly on the effects of degenerate coefficients in wetting and drying problems.