FEM2D_POISSON_CG_ELL
A Problem in an L-shaped Region

FEM2D_POISSON_CG_ELL is a FORTRAN90 library which defines the geometry of an L-shaped region, as well as boundary conditions for a given Poisson problem, and is called by FEM2D_POISSON_CG as part of a solution procedure.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

FEM2D_POISSON_CG_ELL is available in a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

FEM2D_POISSON_CG, a FORTRAN90 program which solves Poisson's equation on a triangulated region, using the finite element method, sparse storage, and a conjugate gradient solver.

FEM2D_POISSON_CG_BAFFLE, a FORTRAN90 library which defines the geometry of a channel with 13 hexagonal baffles, as well as boundary conditions for a given Poisson problem, and is called by fem2d_poisson_cg as part of a solution procedure.

FEM2D_POISSON_CG_LAKE, a FORTRAN90 library which defines the geometry of a lake-shaped region, as well as boundary conditions for a given Poisson problem, and is called by fem2d_poisson_cg as part of a solution procedure.

Reference:

1. Hans Rudolf Schwarz,
   Methode der Finiten Elemente,
   Teubner Studienbuecher, 1980,
   ISBN: 3-519-02349-0.
2. Gilbert Strang, George Fix,
   An Analysis of the Finite Element Method,
   Cambridge, 1973,
   ISBN: 096140888X,
   LC: TA335.S77.
3. Olgierd Zienkiewicz,
   The Finite Element Method,
   Sixth Edition,
   Butterworth-Heinemann, 2005,
   ISBN: 0750663200.

Source Code:

• ell.f90, the user-supplied routines to evaluate the right hand side, linear coefficient, and boundary conditions;
• ell_nodes.txt, a text file containing a list, for each node, of its X and Y coordinates;
• ell_nodes.png, a PNG image of the nodes;
• ell_elements.txt, a text file containing a list, for each element, of the three nodes that compose it;
• ell_elements.png, a PNG image of the element mesh;

Examples and Tests:

• ell.txt, the output file;
• ell_values.txt, a text file containing the solution U at each node (X,Y);

You can go up one level to the FORTRAN90 source codes.