SED2D solution files and buffer files are written in a binary form. Binary files are
strictly associated with the type of system upon which they are created. Word size
and record length may be different from one system to the next.
Note: The computer identification is vital only if there is insufficient memory
allotted during execution of SED2D which would require it to write temporary buffer
files to solve the large matrix.
Want You Need To Do About It?
Tell SED2D what type of system on which you will be running by providing a value
for the machine identifier with the $M card. The type of computer you specify
determines how temporary buffer files will be written and read.
The $M card is necessary if your system does not have enough memory available for
the simulation. In this case, SED2D will write temporary buffer files to your disk.
Example: If you are running SED2D on a DOS or Windows-95/98 ir
Windows 2000 based PC, the machine identifier value should be 1.
Running on a PC
Obtaining The Mesh Geometry
As with all of the TABS-MD system numerical models, the finite element mesh is
typically constructed with a graphical user interface, such as SMS, then processed
through the GFGEN program.
A basic rule for constructing a finite mesh geometry to represent a given problem, is
to move the boundaries of the model far enough from the area of primary interest
such that if something is happening at the boundary its effect will be insignificant in
the area of interest. When transport simulations follow a hydrodynamic study, it is
imperative to consider transport issues when defining the model domain and its
corresponding boundary condition locations.
First, you may directly input from within the SED2D run control file the information
for all nodes and for all elements. The GE-, GNN-, and GW- cards may be used to
directly specify the finite element mesh for the SED2D simulation. This manual
technique is very rare and typically only used to illustrate analytical test cases.
The second, and more accurate method is to provide SED2D with a geometry input
file containing the nodal assignments and element connections. The binary geometry
file created by GFGEN is the ideal way to communicate the finite element mesh to
In almost all model applications the mesh geometry used in RMA2 and SED2D
should be identical. The one notable exception would be a deliberate IMAT=0
34 Using SED2D
Users Guide To SED2D-WES