4.2.2 Grid-, Model- and Quantity Definitions

After definition of the global sections the system needs more detailed information about the mesh-structure and how to initialize the quantities that are to be calculated. Therefore a grid section has to be defined supporting the following syntax

Grid = <gridname>       # Read a grid named <gridname> from 
                        # the defined source file
{
    <source definition> # overwrite global source definition file
    <model definition>  # initialize the analytical model
    <output definition> # overwrite global output definition file
}

where Grid is a keyword and <gridname> must be a valid name of a mesh within the chosen source.

As can be seen a local source and output definition is possible but not obligatory. If they are defined, they overwrite the previously defined global sources. The <model definition section> is a means to map the analytical model defined in the AMI onto the selected grid. To have access to the analytic variables of the model a function-like syntax is used:

Model = <ModelName>(<Q1>,<Q2>,<Q3>,<Q4>,<...>)
{
     <initialize quantities>      # initializing quantities
     <scale quantities>           # scaling of quantities
     <limit quantities>           # set limitations
     <epsilon criterion>          # Newton iteration limit
     <quantity update-mode>       # selective update modes
     <auxiliary definition>       # auxiliary definition 
     <limits for grid-adaptation> # limits for refinement
                                  # and coarsement
}

Again Model is a keyword. <ModelName> is the name of the discretized analytical model defined in the Analytical Model Interface (described in detail in section 4.3). <Q1>,<Q2> to <Qn> are the user defined quantity names that have to be unambiguous for later boundary definitions. Various additional features are definable but only the initialization of quantities is obligatory.