Assumptions
1. Files
a. Suffix
Geometry file(s) will end exactly in '.cas' or '.cas.gz'
Data file(s) will end exactly in '.dat' or '.dat.gz'
b. Number of files
There will be at least one .cas file.
There will be one of the two options:
same number of cas and dat files
one cas and multiple dat files
c. Multiple files are entered into the EnSight reader using an asterisk '*'
For example, with the following files:
file_10100.cas, file_10200.cas, file_10300.cas, ...., file_11000.cas
file_10100.dat, file_10200.dat, file_10300.dat, ...., file_11000.dat
Enter the following to read all these files
Set cas .cas.gz: file_*.cas
Set .dat .dat.gz: file*_.dat
d. Formats
Both the cas and dat file can be in the following format:
ASCII
binary single precision
binary double precision
e. Endian
Binary files can be either LittleEndian or BigEndian format
but both cas and dat must be the same format
f. Compressed files. Files can be compressed using gzip.
In this case suffix must be .dat.gz or .cas.gz
Expect gzip files to read approximately twice as slow as uncompressed files
g. Meta files
2. FLUENT Beta Reader options - Click on the 'Format options' tab in the
data reader dialog after selecting the 'FLUENT Beta' reader.
a. Load Internal Parts toggle. The internal faces that are used to construct the
cells are not loaded by default. Toggle this ON and you will be able to get access
to these parts. If you do toggle this on, then it is recommended that you click
on the 'Choose Parts' button rather than 'Load all' when you are finished entering
in your filenames, as you'll only want to load the interior parts that are necessary
to save memory and time.
b. Use Meta Data Files toggle. The data in the FLUENT files is distributed inside of
the .cas and .dat files. Allowing the reader to write out Meta Files that map the
locations of important data can provide a significant speed up the next time you
access that timestep. It is recommended that you leave this toggle ON. If you have
write permission in the directory where your data is located, three types of binary
Meta Files will be written when you first access each file, with extensions
.EFC for the cas file, .EFD for the .dat file and .EFG for the time-history data. They
are optional and if you don't have write permission, the reader will read the entire file
to find the relevant data each time you come back to that timestep.
c. Console Output Pulldown. - Leave it at Normal Output to see very little output in
the server console window. Verbose output will be useful to tell you every FLUENT
part that is in the dataset, whether it is interior or not, and whether it is skipped,
and to echo it's Ensight Part number. Debug output is useful if you have problems.
d. Time Values Pulldown - Default is 'Calc Const Delta', to read a delta time from one
file and calculate the time values from that. If you choose 'Read Time Values' then
the reader will open each file and find the exact time value. This will be stored in
the EFG file if you've not disabled Meta Files. Finally, the simplest is to 'Use File
Steps' which will just use the file step number as the time value. This is quick, but
is not a good idea if you need real time for anything such as particle tracing.
2. Parts - EnSight parts have a FLUENT number which goes from 1 to the number of
parts found in the cas file. It is expected that the number of parts does not
change over time from cas file to cas file, however the number of elements and
their connectivity can change from cas file to cas file.
a. Mapping - FLUENT parts are skipped if they have no elements, or if they are interior
parts and you've chosen not to load them. Therefore the EnSight part list is a subset
of the FLUENT part list. If you wish to see this echoed out to the console, then turn
on Verbose Console Output in the Format Options Tab.
b. Interior Parts - Parts of FLUENT Type 'Interior' are not loaded by default. See above
for instructions on loading interior parts. Again, if you chose to do this, click on
the Choose parts button in the Reader Dialog and pick the parts you want to avoid
loading the unnecessary interior parts.
c. IDs. Parts have node and element ids to enable querying your data. Node ids are
created from the coordinate global node. Element ids are arbitrarily created in
sequence and are non-unique.
3. Transient data
Time in FLUENT is stored in section 37 of the cas (or dat) file
Lots of stuff is stored this section, but for our purposes
three time values are stored under section 37
Suppose you have time_step delta time total time
Filename 'time-step' 'physical-time-step' 'flow-time'
file0005.cas 5 0.002 0.01
file0010.cas 10 0.002 0.02
... ... ... ...
file0100.cas 100 0.002 0.20
a. 'time-step' - The step number (appears to be correlated to the file number).
Note that the EnSight timestep is shifted to start at timestep 0.
That is, file4000001.cas becomes timestep 0, file4000002 becomes timestep 1, etc.
b. 'physical-time-step' - The delta time value for ONE step.
c. 'flow-time' - The total time (time-step physical-time-step)
Based on the value Time Values Pulldown in the Format Options tab of the data reader dialog,
the solution time is one of the following:
a. 'Calc Const Delta' - calculated using delta time(ensight timestep) (default) .
Delta time is assumed constant and read from one file
b. 'Read Time Values' - time value is read from each .cas file (open/close each file can be very time consuming)
if this option is chosen, these values should be CACHED in a meta-file for later reads.
c. 'Use File Steps' - time value is integer 0 to number of timesteps
4. Variables
a. Location - Variables that are cell-centered remain where they are solved,
that is the reader does not interpolate the cell-centered variables
to the nodes. This is better than the current FLUENT export to EnSight
which averages the variables to the nodes leading to flow into and out of
walls which causes particles to stop prematurely and skews mass flow calculations.
b. Parts - Not all variables exist on all parts. If you select a part and color by a
variable and get undefined, then load the data using Verbose mode and take
a look at the console. Your variable is probably not defined for this part.
c. Many variables that formerly were named improperly have been fixed.
However if you see a variable that is not named properly, send the variable number and what it
should be named to
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and we'll fix it.
5. Previous FLUENT reader
Environmental variables from the previous reader are recognized and if they are set are
interpreted as follows
a. Set Verbose Console output:
DFLUENT_SHOW_VARS -
DFLUENT_VOICE_TRANSIENT_FILES
DFLUENT_VOICE_FILES_LOADED
DFLUENT_VOICE_COMMENTS
DFLUENT_VOICE_DECLARATIONS
DFLUENT_VOICE_ZONE_NAMES
DFLUENT_VOICE_VARS_FOUND
DFLUENT_VOICE_VARS_LOADED
DFLUENT_VOICE_PARTS_LOADED
DFLUENT_VOICE_CHECK_PROGRESS
b. Alternatives to using the Data Reader Dialog (Not it's better not to use these,
and to make your choices from the reader, as then your choices will be recorded into
command language and you won't have to remember to set these environmental variables ).
DFLUENT_DO_CHECK - Ignored, as Beta reader always does geometry checking
DFLUENT_SHOW_INT_PARTS - Loads internal parts
c. The following are not used
DFLUENT_IGNORE_VARS - Ignored as variables are only loaded when you use them
DFLUENT_VOICE_ERRORS - Ignored in this reader: Errors always voiced
6. This reader has been enabled for SOS. Please report your SOS problems to
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.
Extra Technical Details
The following FLUENT cell types are expected:
TRI03 (triangular cell),
TET04 (tetrahedral cell),
QUA04 (quadrilateral cell),
HEX08 (hexahedral cell),
PYR05 (pyramid cell),
PEN06 (wedge cell).
The following FLUENT face types are expected:
BAR02 (2-node bar face),
TRI03 (triangular face),
QUA04 (quadrilateral face).
The following FLUENT section types are recognized in the CASE file:
2 (grid dimensionality),
4 (machine configuration data),
10, 2010, 3010 (nodes positions: ASCII, float, double precision format),
12, 2012, 3012 (cells descriptions: ASCII, float, double precision format),
13, 2013, 3013 (faces descriptions: ASCII, float, double precision format),
39 (zone names).
Still To Do:
- IcePak format
- Mole species’ calculations
- Polyhedral mesh
- Backup implementation
- User defined variables
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