Getting user values

When running user written routines it is often convenient to set values in the Graphical User Interface and pass these to the subroutine. This can be done by using the Card 9 - VARIABLE Variable Definition Card - Optional. For more information, see the Thermal Solver Reference Manual PDF.

A user written subroutine can access these values by calling the subroutine VARVAL. For example, to get the value of NAME the call is:

call varval("%NAME", value)

This reads the value from NAME and assigns it to the variable value. Notice the "%" character at the start of the variable name.

Variables can be defined using thermal solver generic entities using the format described below for the include file. A generic entity directly defines a line to be added to the input file.

Variables can also be set in an include file, in which case any name can be used. The syntax of the Card 9 - VARIABLE Variable Definition Card - Optional entry is:

VARIABLE %NAME value

where:

%NAME is the variable name preceded by a "%" character and value is the value to be assigned. An include file must include all delimiters and so a complete include file that sets variables AREA and ALTITUD looks like:

Include file for User1 Variables
-1
-1
-1
-1
-1
-1
-1
-1 
VARIABLE %AREA 6.789 
VARIABLE %ALTITUD 25000
-1
-1

The code to access these variables would then be:

 real area, altitude
        ..
        call varval('%AREA', area)
        call varval('%ALTITUD', altitude)

Variable values can obviously have many uses, one of these is to switch features of a user written subroutine on or off. The following code will execute the subroutine APPLYHEAT if the variable TMGVAR0 > 0 and the routine APPLYCONVECT if the variable TMGVAR2 > 0:

 logical doheat, doconvect
        real tempvar
        ..
C
C     Initialization code
C
        call varval('%TMGVAR0',tempvar)
        if (tempvar .gt. 0.0) then
                doheat = .true.
        else
                doheat = .false.
        end if
        call varval('%TMGVAR1',tempvar)
        if (tempvar .gt. 0.0) then
                doconvect = .true.
        else
                doconvect = .false.
        end if
        ..
C
C   Implementation code
C
        if(doheat)then
                call applyheat(…
        end if
        if(doconvect)then
                call applyconvect(…
        end if

Note that, the default values, for all TMG variables, is zero. Therefore, in the above example, the routines APPLYHEAT and APPLYCONVECT will not run unless they are explicitly turned on. The advantage of using this control logic is that the two routines can be combined into a single USER1 routine and then selected independently. Without the control logic, the following three versions of USER1 would be required:

Contains calls to both routines
Contains call to APPLYHEAT only
Contains call to APPLYCONVECT only

Selection of routines to be run using this multiple routine approach would be by selecting the appropriate include file.