thunderegg

This is a library for solving Poisson's equation on adaptively refined block-structured Cartesian grids in two and three dimensions in a distributive parallel environment.

The code offers two solvers:

• Domain decomposition using a Schur complement, which is solved using GMRES preconditioned with BoomerAMG.

• Geometric multigrid method using a Fast Adaptive Composite (FAC) type algorithm.

The Schur complement method works well for 2D problems, but not 3D. The Geometric multigrid method works well for both 2D and 3D.

Members of the team :

• Scott Aiton
• Donna Calhoun
• Grady Wright

Required Software

• FFTW
• Zoltan
• PETSc
• CMake

Compiling

Create a seperate source directory and run cmake in the build directory:

$ cd build_dir
$ cmake /path/to/source

Compilers can be specified in the following way

$ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER /path/to/source

Paths to libraries can be specified with the following cmake options

-DFFTW_DIR=/path/to/library
-DPETSC_DIR=/path/to/library
-DZOLTAN_DIR=/path/to/library

Then compile with make:

make

Examples:

Both of these examples support both the Schur compliment and geometric multigrid methods:

• apps/2d/steady2d : Two dimensional example for Poisson's equation
• apps/3d/steady : Three dimensional example for Poisson's equation