10.5. FAST UNSTRUCTURED Results File Format

FAST UNSTRUCTURED input data consists of the following:

  • Geometry file (required) (GRID file).

  • Results file (optional).

  • EnSight5 Measured/Particle Files (optional). The measured .res file references the measured geometry and variable files.

FAST UNSTRUCTURED data files can be read as:

  • Workstation: ASCII, C Binary, or FORTRAN binary

  • Cray: ASCII, C Binary, or COS-Blocked FORTRAN binary

Due to the different number of representations on a Cray Research vector system and workstations, binary files created on a Cray Research vector system can not be read on the workstation, and visa versa.

EnSight reads the geometry (grid files) directly. However, an EnSight-like results file is needed in order to read the results unless a "standard" Q-file is provided in its place. See FAST UNSTRUCTURED Result File below.

FAST UNSTRUCTURED Geometry file notes

Only the single zone format can be read into EnSight. Any tetrahedral elements will be placed into the first "domain" Part. Triangular elements are placed into Parts based on their "tag" value.

The FAST UNSTRUCTURED solution file or function file formats can be used for variable results. The I J K values need to be I=Number of points and J=K=1. This does require the use of a modified EnSight results file as explained below.

Node and element numbers are assigned sequentially allowing for queries to be made within EnSight. Tetrahedron elements will be assigned before triangular elements.

FAST UNSTRUCTURED Result file format

The FAST UNSTRUCTURED result file was defined by Ansys and is very similar to the EnSight results file and contains information needed to relate variable names to variable files, step information, etc. There is a slight variation from the normal EnSight results file because of the differences between the solution (Q file) and function files. The difference lies on the lines which relate variable filenames to a description. These lines have the following format:

<filename> <type> <number(s)> <description>

See FAST UNSTRUCTURED Result File below for the definition of each.

The following information is included in a FAST UNSTRUCTURED result file:

  • Number of scalar variables

  • Number of vector variables

  • Number of time steps

  • Starting file number extension and skip-by value

  • Flag that specifies whether there is changing geometry.

  • Names of the files that contain the values of scalar and vector variables. An indication as to the type of the file being used for the variable, which variable in the file and the name given to that variable.

  • The names of the geometry files that will be used for the changing geometry.

Generic FAST UNSTRUCTURED Result File Format

The format of the Result file is as follows:

  • Line 1

    Contains the number of scalar variables, the number of vector variables and a geometry changing flag. If the geometry changing flag is 0, the geometry of the model does not change over time. If the flag is 1, the geometry can change connectivity. If the flag is 2, only coordinates can change.

  • Line 2

    Indicates the number of time steps that are available. If this number is positive, then line 3 information must be present. If this number is negative, then Line 3 information must not be present and the times will be read from the solution file. Thus, one must have a solution file in one of the lines from Line 6 on.

  • Line 3

    Lists the time that is associated with each time step. There must be the same number of values as are indicated in Line 2. This "line" can actually span several lines in the file. Specify only if Line 2 value is positive.

  • Line 4

    Specified only if more than one time step is indicated in Line 2. The two values on this line indicate the file extension value for the first time step and the offset between files. If the values on this line are 0 5, the first time step available has a subscript of 0, the second time step available has a subscript of 5, the third time step has a subscript of 10, and so on.

  • Line 5

    This line exists only if the changing geometry flag on Line 1 has been set to 1 or 2. Line contains name of the FAST UNSTRUCTURED grid file. The file name must follow the EnSight wild card specification.

  • Line 6 through Line [5+N] where N is the number of scalar variables specified in Line 1.

    List the file names that correspond to each scalar variable. There must be a file name for each scalar variable that is specified in Line 1. If there is more than one time step, the file name must follow the EnSight wild card specification.

    These lines also contain the type of file being used, solution or function, and the location of the variable value in the file. The contents are:

    <filename> <type> <number> <description>

    where filename is the name of solution file or function file containing the variable; type is "S" for solution file, or "F" for function file; number is which variable in the file to use (specify just one number); and description is the Description of the variable.

    The solution file ("s") is the traditional .q file in which normally the first variable is density, the second through fourth variables are the components of momentum, and the fifth variable is total energy.

  • Lines that follow the scalar variable files.

    List the file names that correspond to each vector variable. There must be a file name for each vector variable that is specified in Line 0. If there is more than one time step, the file name must follow the EnSight wild card specification.

    These lines also contain the type of file being used, solution or function, and the location(s) of the variable values in the file. The contents are:

    <filename> <type> <numbers> <description>

    where filename is the name of solution file or function file containing the variable; type is "S" for solution file, or "F" for function file; numbers are which variables in the file to use (specify just three numbers); and description is the Description of the variable.

The generic format of the result file is as follows:

#_of_scalars #_of_vectors geom_chng_flag
#_of_timesteps
time1 time2 time3 .....
start_file_# skip_by_value
geometry_file_name.geo**
scalar0_file_name** type # description
scalar1_file_name** type # description
.
.
.
vector0_file_name** type # # # description
vector1_file_name** type # # # description
.
.
.

FAST UNSTRUCTURED This example illustrates a result file that specifies a non-changing geometry with

Example only one time step.

3 2 0
1
0.0
block.sol S 1 Density
block.sol S 5 Total_Energy
block.scl F 1 Temperature
block.var F 1 2 3 Displacement
block.sol S 2 3 4 Momentum

Thus, this model will get two scalars from the solution file (block.sol). The first is Density in the first location in the file and the next is Total energy in the fifth location in the solution file. It will also get a Temperature scalar from the first location in the function file (block.scl).

It will get a Displacement vector from the function file called block.var. The three components of this vector are in the 1st, 2nd, and 3rd locations in the file. Finally, a Momentum vector will be obtained from the 2nd, 3rd, and 4th locations of the solution file.

Example 2 is somewhat similar, except that it is transient, with coordinate changing geometry.

Note:  The times will come from the solution file.

3 2 2
-10
0 1
block***.grid
block***.sol S 1 Density
block***.sol S 5 Total_Energy
block***.scl F 1 Temperature
block***.var F 1 2 3 Displacement
block***.sol S 2 3 4 Momentum