7.9. Average Region

7.9.1. Average Region

Scope: Fuego Procedure
Summary: Contains the commands needed to execute an analysis on this region.

begin Average Region Regionname

   Use Finite Element Model ModelName [ Model Coordinates Are Nodal_variable_name  ]

   begin Heartbeat Label
   end

   begin Heartbeat Output Label
   end

   begin History Output Label
   end

   begin Restart Data Label
   end

   begin Results Output Label
   end

   begin Solution Options OptionsName
   end

end Average Region Regionname

7.9.1.1. Line Commands

Use Finite Element Model

Syntax: Use Finite Element Model ModelName [ Model Coordinates Are Nodal_variable_name ]
Summary: Associates a predefined finite element model with this region.

Parameter	Value	Default
ModelName	string	–

7.9.2. History Output

Scope: Average Region, Fuego Region, Input_Output Region, Particle Region
Summary: Describes the location and type of the output stream used for outputting history for the enclosing region.

begin History Output Label

   Additional Steps {=} List_of_steps...

   Additional Times {=} List_of_times...

   At Step n {increment | interval} {=} m

   At Time Dt1 {increment | interval} {=} Dt2

   Auto Output {all | element | global | nodal} User Defined Variables [ In UserOutputHistoryList...  ]

   Database Name {=} StreamName

   Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}

   Element [ VariableList...  ]

   Exists {=} {abort | add_suffix | append | overwrite}

   Face [ VariableList...  ]

   Flush Interval {=} Option

   Global [ Variables...  ]

   Nodal [ VariableList...  ]

   Node [ VariableList...  ]

   Nodeset [ VariableList...  ]

   Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}

   Overwrite {=} {false | no | off | on | true | yes}

   Property PropertyName {=} PropertyValue

   Start Time {=} Start_time

   Synchronize Output

   Termination Time {=} Final_time

   Timestep Adjustment Interval {=} Nsteps

   Title

   Use Dynamic Topology Io

   Use Output Scheduler Timer_name

   Variable {=} {edge | element | face | global | nodal | node} Variable_list...

end History Output Label

7.9.2.1. Line Commands

Additional Steps

Syntax: Additional Steps {=} List_of_steps…
Summary: Additional simulation steps when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_steps	integer…	–

Additional Times

Syntax: Additional Times {=} List_of_times…
Summary: Additional simulation times when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_times	real…	–

At Step

Syntax: At Step n {increment | interval} {=} m
Summary: Specify an output interval in terms of the internal iteration step count. The first step specifies the step count at the beginning of this interval and the second step specifies the output frequency to be used within this interval.

Parameter	Value	Default
n	integer	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
m	integer	–

At Time

Syntax: At Time Dt1 {increment | interval} {=} Dt2
Summary: Specify an output interval in terms of the internal simulation time. The first time specifies the time at the beginning of this time interval and the second time specifies the output frequency to be used within this interval.

Parameter	Value	Default
Dt1	real	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
Dt2	real	–

Auto Output

Syntax: Auto Output {all | element | global | nodal} User Defined Variables [ In UserOutputHistoryList… ]
Summary: Allows users to automatically output all user output defined variables for the type requested.

Parameter	Value	Default
auto_output_type_2	{all \| element \| global \| nodal}	–

Database Name

Syntax: Database Name {=} StreamName
Summary: The base name of the database containing the output history. If the filename begins with the ‘/’ character, it is an absolute path; otherwise, the path to the current directory will be prepended to the name. If this line is omitted, then a filename will be created from the basename of the input file with a “.h” suffix appended.

Parameter	Value	Default
{=}	{= \| are \| is}	–
StreamName	string	–

Database Type

Syntax: Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}
Summary: The database type/format to be used for the output history.

Parameter	Value	Default
{=}	{= \| are \| is}	–
DatabaseTypes	{catalyst \| catalyst_exodus \| cgns \| dof \| dof_exodus \| exodus \| exodusii \| exonull \| generated \| genesis \| null \| parallel_exodus \| textmesh}	–

Element

Syntax

Element [ VariableList… ]

Summary

Define the element variables that should be written to the history database. The syntax is: “element {internal_name} at element {id} as {DBname}” or “element {internal_name} nearest location X, Y, Z as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Exists

Syntax: Exists {=} {abort | add_suffix | append | overwrite}
Summary: Specify the behavior when creating this database and there is an existing file with the same name. The default behavior is “OVERWRITE” which deletes the existing file and creates a new file of the same name. “APPEND” will (if possible) append the new data to the end of the existing file. “ABORT” will print an error message and end the analysis. “ADD_SUFFIX” will add a -s???? suffix where the ???? is replaced by a sequential number starting at 0002.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{abort \| add_suffix \| append \| overwrite}	–

Face

Syntax

Face [ VariableList… ]

Summary

Define the face variables that should be written to the history database. The syntax is: “face {internal_name} at face {id} as {DBname}” or “face {internal_name} nearest location X, Y, Z as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Flush Interval

Syntax: Flush Interval {=} Option
Summary: The minimum time interval (in seconds) at which output will be explicitly flushed to disk. The default is 10 seconds.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Option	integer	10

Global

Syntax

Global [ Variables… ]

Summary

Define the global/reduction variables that should be written to the history database. The syntax is: “global {internal_name} as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Nodal

Syntax

Nodal [ VariableList… ]

Summary

Define the nodal variables that should be written to the history database. The syntax is: “nodal {internal_name} at node {id} as {DBname}” or “nodal {internal_name} nearest location X, Y, Z as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Node

Syntax

Node [ VariableList… ]

Summary

Define the nodal variables that should be written to the history database. The syntax is: “node {internal_name} at node {id} as {DBname}” or “node {internal_name} nearest location X, Y, Z as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Nodeset

Syntax

Nodeset [ VariableList… ]

Summary

Define the nodeset variables that should be written to the history database. The syntax is: “nodeset {internal_name} at node {id} as {DBname}” or “nodeset {internal_name} nearest location X, Y, Z as {DBname}”.

Where {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Output On Signal

Syntax: Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}
Summary: When the specified signal is raised, the output stream associated with this block will be output.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Signals	{sigabrt \| sigalrm \| sigfpe \| sighup \| sigill \| sigint \| sigkill \| sigpipe \| sigquit \| sigsegv \| sigterm \| sigusr1 \| sigusr2}	–

Overwrite

Syntax: Overwrite {=} {false | no | off | on | true | yes}
Summary: (DEPRECATED, Use EXISTS) Specify whether the database should be overwritten if it exists. The default behavior is to overwrite unless this command is specified in the output block and either off, false, or no is specified.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{false \| no \| off \| on \| true \| yes}	–

Property

Syntax

Property PropertyName {=} PropertyValue

Summary

Define a database property named “PropertyName” with the value “PropertyValue”. If PropertyValue consists of all digits, it will define an integer property. If PropertyValue is “true” or “yes” or “false” or “no”, it will define a logical property; otherwise it will define a string property. Supported properties are typically database dependent; Some history-related properties are:

VARIABLE_NAME_CASE = upper|lower
MAX_NAME_LENGTH = value (32)

Parameter	Value	Default
PropertyName	string	–
{=}	{= \| are \| is}	–
PropertyValue	string	–

Start Time

Syntax: Start Time {=} Start_time
Summary: Specify the time to start outputting results from this output request block. This time overrides all ‘at time’ and ‘at step’ specifications.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Start_time	real	–

Synchronize Output

Syntax

Synchronize Output

Summary

In an analysis with multiple regions, it is sometimes desirable to synchronize the output of results data between the regions. This can be done by adding the SYNCHRONIZE OUTPUT command line to the results output block. If a results block has this set, then it will write output whenever a previous region writes output. The ordering of regions is based on the order in the input file, algorithmic considerations, or by solution control specifications.

Although the USE OUTPUT SCHEDULER command line can also synchronize output between regions, the SYNCHRONIZE OUTPUT command line will synchronize the output with regions where the output frequency is not under the direct control of the Sierra IO system. Examples of this are typically coupled applications where one or more of the codes are not Sierra-based applications such as Alegra and CTH. A results block with SYNCHRONIZE OUTPUT specified will also synchronize its output with the output of the external code.

The SYNCHRONIZE OUTPUT command can be used with other output scheduling commands such as time-based or step-based output specifications.

Termination Time

Syntax: Termination Time {=} Final_time
Summary: Specify the time to stop outputting results from this output request block.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Final_time	real	–

Timestep Adjustment Interval

Syntax: Timestep Adjustment Interval {=} Nsteps
Summary: Specify the number of steps to ‘look ahead’ and adjust the timestep to ensure that the specified output times or simulation end time will be hit ‘exactly’.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Nsteps	integer	–

Title

Syntax: Title
Summary: Specify the title to be used for this specific output block.

Use Dynamic Topology Io

Syntax: Use Dynamic Topology Io
Summary: Specify that the app use IO for dynamic topology modifications where the output files are stored in a single database. Legacy file format for dynamically changing topology results in the creation of multiple files for each output on a mesh modification. This option leverages the ability of netCDF to create mesh groups within a single database and concatenate all mesh files into one. The names of each mesh group are of the form IOSS_MESH_GROUP-??? where ??? is the 1-based output index 1, 2, …, 10, …., 100, … Please note that netCDF has a current limit of 65,536 groups

Use Output Scheduler

Syntax: Use Output Scheduler Timer_name
Summary: Associates a predefined output scheduler with this output block (results, restart, heartbeat, or history).

Parameter	Value	Default
Timer_name	string	–

Variable

Syntax

Variable {=} {edge | element | face | global | nodal | node} Variable_list…

Summary

Define the variables that should be written to the history database. The syntax is: “variable = entity {internal_name} at entity {id} as {DBname}” or “variable = entity {internal_name} nearest location X, Y, Z as {DBname}” or “variable = entity {internal_name} at location X, Y, Z as {DBname}”.

Where {entity} is ‘node’, ‘element’, ‘face’, or ‘edge’; {internal_name} is the name of the variable in the Sierra application; and {DBname} is the name as it should appear on the history database.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Option	{edge \| element \| face \| global \| nodal \| node}	–
Variable_list	string…	–

7.9.3. Restart Data

Scope: Average Region, Fuego Region, Input_Output Region, Particle Region
Summary: Describes the data required to output and input restart data for the enclosing region.

begin Restart Data Label

   Additional Steps {=} List_of_steps...

   Additional Times {=} List_of_times...

   At Step n {increment | interval} {=} m

   At Time Dt1 {increment | interval} {=} Dt2

   At Wall Time Dt1 {increment | interval} {=} Dt2

   Component Separator Character {=} Separator

   Cycle Count {=} Count

   Database Name {=} StreamName

   Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}

   Debug Dump

   Decomposition Method {=} {block | cyclic | external | geom_kway | hsfc | kway | kway_geom | linear | map | metis_sfc | random | rcb | rib | variable}

   Exists {=} {abort | add_suffix | append | overwrite}

   File Cycle Count {=} Count

   Input Database Name {=} StreamName

   Optional

   Output Database Name {=} StreamName

   Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}

   Output Restart State {=} {off | on}

   Overlay Count {=} Count

   Overwrite {=} {false | no | off | on | true | yes}

   Property PropertyName {=} PropertyValue

   Restart {=} {auto}

   Restart Time {=} Time

   Start Time {=} Start_time

   Synchronize Output

   Shift To Start Time

   Termination Time {=} Final_time

   Timestep Adjustment Interval {=} Nsteps

   Use Dynamic Topology Io

   Use Output Scheduler Timer_name

end Restart Data Label

7.9.3.1. Line Commands

Additional Steps

Syntax: Additional Steps {=} List_of_steps…
Summary: Additional simulation steps when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_steps	integer…	–

Additional Times

Syntax: Additional Times {=} List_of_times…
Summary: Additional simulation times when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_times	real…	–

At Step

Syntax: At Step n {increment | interval} {=} m
Summary: Specify an output interval in terms of the internal iteration step count. The first step specifies the step count at the beginning of this interval and the second step specifies the output frequency to be used within this interval.

Parameter	Value	Default
n	integer	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
m	integer	–

At Time

Syntax: At Time Dt1 {increment | interval} {=} Dt2
Summary: Specify an output interval in terms of the internal simulation time. The first time specifies the time at the beginning of this time interval and the second time specifies the output frequency to be used within this interval.

Parameter	Value	Default
Dt1	real	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
Dt2	real	–

At Wall Time

Syntax: At Wall Time Dt1 {increment | interval} {=} Dt2
Summary: Write a restart file at a specific wall time since the start of the run. Time string format allows s, m, h, d for seconds, minutes, hours, days

Parameter	Value	Default
Dt1	string	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
Dt2	string	–

Component Separator Character

Syntax: Component Separator Character {=} Separator
Summary: The separator is the single character used to separate the output variable basename (e.g. “stress”) from the suffices (e.g. “xx”, “yy”) when displaying the names of the individual variable components. For example, the default separator is “_”, which results in names similar to “stress_xx”, “stress_yy”, … “stress_zx”. To eliminate the separator, specify an empty string (“”) or NONE.

Parameter	Value	Default
{=}	{= \| is}	–
Separator	string	–

Cycle Count

Syntax: Cycle Count {=} Count
Summary: Specify the number of restart steps which will be written to the restart database before previously written steps are overwritten. For example, if the cycle count is 5 and restart is written every 0.1 seconds, the restart system will write 0.1, 0.2, 0.3, 0.4, 0.5 to the database. It will then overwrite the first step with data from time 0.6, the second with time 0.7. At time 0.8, the database would contain data at times 0.6, 0.7, 0.8, 0.4, 0.5. Note that time will not necessarily be monotonically increasing on a database that specifies the cycle count.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Count	integer	–

Database Name

Syntax: Database Name {=} StreamName
Summary: The database containing the input and/or output restart data. If this analysis is being restarted, restart data will be read from this file. If the analysis is writing restart data, the data will be written to this file. It will be overwritten if it exists (after being read if applicable). If the filename begins with the ‘/’ character, it is an absolute path; otherwise, the path to the current directory will be prepended to the name. See also the ‘Input Database’ and ‘Output Database’ commands.

Parameter	Value	Default
{=}	{= \| are \| is}	–
StreamName	string	–

Database Type

Syntax: Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}
Summary: The database type/format used for the restart file.

Parameter	Value	Default
{=}	{= \| are \| is}	–
DatabaseTypes	{catalyst \| catalyst_exodus \| cgns \| dof \| dof_exodus \| exodus \| exodusii \| exonull \| generated \| genesis \| null \| parallel_exodus \| textmesh}	–

Debug Dump

Syntax: Debug Dump
Summary: Specify whether the restart system will write the restart data immediately after reading the restart data if the run is restarting. The output data can be compared with the restart input data to determine whether they match.

Decomposition Method

Syntax: Decomposition Method {=} {block | cyclic | external | geom_kway | hsfc | kway | kway_geom | linear | map | metis_sfc | random | rcb | rib | variable}
Summary: The decomposition algorithm to be used to partition elements to each processor in a parallel run.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Method	{block \| cyclic \| external \| geom_kway \| hsfc \| kway \| kway_geom \| linear \| map \| metis_sfc \| random \| rcb \| rib \| variable}	–

Exists

Syntax: Exists {=} {abort | add_suffix | append | overwrite}
Summary: Specify the behavior when creating this database and there is an existing file with the same name. The default behavior is “OVERWRITE” which deletes the existing file and creates a new file of the same name. “APPEND” will (if possible) append the new data to the end of the existing file. “ABORT” will print an error message and end the analysis. “ADD_SUFFIX” will add a suffix to the file name and output to that file.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{abort \| add_suffix \| append \| overwrite}	–

File Cycle Count

Syntax: File Cycle Count {=} Count
Summary: Each restart dump will be written to a separate file suffixed with A,B, … The count specifies how many separate files are used before the cycle repeats. For example, if “FILE CYCLE COUNT = 3” is specified, the restart dumps would be written to file-A.rs, file-B.rs, file-C.rs, file-A.rs, … The maximum value for the cycle count is 26.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Count	integer	–

Input Database Name

Syntax: Input Database Name {=} StreamName
Summary: The database containing the input restart data. If this analysis is being restarted, restart data will be read from this file. See also the ‘Database’ and ‘Output Database’ commands.

Parameter	Value	Default
{=}	{= \| are \| is}	–
StreamName	string	–

Optional

Syntax: Optional
Summary: The database will be read if it exists, but it is not an error if there is no restart database to read for this region during a restarted analysis.

Output Database Name

Syntax: Output Database Name {=} StreamName
Summary: The database containing the output restart data. If the analysis is writing restart data, the data will be written to this file. It will be overwritten if it exists. See also the ‘Database’ and ‘Input Database’ commands.

Parameter	Value	Default
{=}	{= \| are \| is}	–
StreamName	string	–

Output On Signal

Syntax: Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}
Summary: When the specified signal is raised, the output stream associated with this block will be output.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Signals	{sigabrt \| sigalrm \| sigfpe \| sighup \| sigill \| sigint \| sigkill \| sigpipe \| sigquit \| sigsegv \| sigterm \| sigusr1 \| sigusr2}	–

Output Restart State

Syntax: Output Restart State {=} {off | on}
Summary: Outputs the restarted state to the new restarted results file
Description: NOTE: This command must be placed at the Sierra scope of the input file. Allows the analyst to visualize the restarted state for debugging

Parameter	Value	Default
{=}	{= \| are \| is}	–
Option	{off \| on}	–

Overlay Count

Syntax: Overlay Count {=} Count
Summary: Specify the number of restart outputs which will be overlaid on top of the last written step. For example, if restarts are being output every 0.1 seconds and the overlay count is specified as 2, then restart will write times 0.1 to step 1 of the database. It will then write 0.2 and 0.3 also to step 1. It will then increment the database step and write 0.4 to step 2; overlay 0.5 and 0.6 on step 2… At the end of the analysis, assuming it runs to completion, the database would have times 0.3, 0.6, 0.9, … However, if there were a problem during the analysis, the last step on the database would contain an intermediate step.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Count	integer	–

Overwrite

Syntax: Overwrite {=} {false | no | off | on | true | yes}
Summary: (DEPRECATED, Use EXISTS) Specify whether the restart database should be overwritten if it exists. The default behavior is to overwrite unless this command is specified in the restart block and either off, false, or no is specified.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{false \| no \| off \| on \| true \| yes}	–

Property

Syntax

Property PropertyName {=} PropertyValue

Summary

Define a database property named “PropertyName” with the value “PropertyValue”. If PropertyValue consists of all digits, it will define an integer property. If PropertyValue is “true” or “yes” or “false” or “no”, it will define a logical property; otherwise it will define a string property. If PropertyName consists of multiple strings, they will be concatenated together with “_” separating the individual words. Supported properties are typically database dependent; Current properties are:

COMPRESSION_LEVEL = [0..9]
COMPRESSION_SHUFFLE = true|false|on|off
FILE_TYPE = netcdf4 (forces use of netcdf-4 hdf5-based file)
INTEGER_SIZE_DB = 4|8
INTEGER_SIZE_API = 4|8
LOGGING = true|false|on|off
MAX_NAME_LENGTH = value

Parameter	Value	Default
PropertyName	string	–
{=}	{= \| are \| is}	–
PropertyValue	string	–

Restart

Syntax

Restart {=} {auto}

Summary

Specify automatic restart file read.

Description

NOTE: This command must be placed at the Sierra scope of the input file.

Specify that the analysis should be restarted from the last common time on all restart databases for each Region in the analysis. In addition to this line command, each Region in the analysis (strictly, only the region(s) that will be restarted) must have a restart block specifying the database to read the restart state data.

By default, use of this command will not cause output files (e.g., results, history, heartbeat, restart) to be overwritten. Instead output files will be written with the same basename and the suffix -s000*. Common visualization packages are written to handle this file organization gracefully in order for the user to view all results seamlessly.

Parameter	Value	Default
{=}	{= \| are \| is}	–
{auto}	{auto \| automatic}	–

Restart Time

Syntax

Restart Time {=} Time

Summary

Specify restart file read at a specified time.

Description

NOTE: This command must be placed at the Sierra scope of the input file.

Specify the time that the analysis will be restarted. In addition to this line command, each Region in the analysis (strictly, only the region(s) that will be restarted) must have a restart block specifying the database to read the restart state data. The restart ‘time’ must be greater than zero and less than or equal to the termination time.

By default, use of this command will cause previous output files (e.g., results, history, heartbeat, restart) to be overwritten. If this command is chosen, the onus is placed on the user to ensure that previous output files are not overwritten.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Time	real	–

Start Time

Syntax: Start Time {=} Start_time
Summary: Specify the time to start outputting results from this output request block. This time overrides all ‘at time’ and ‘at step’ specifications.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Start_time	real	–

Synchronize Output

Syntax

Synchronize Output

Summary

In an analysis with multiple regions, it is sometimes desirable to synchronize the output of results data between the regions. This can be done by adding the SYNCHRONIZE OUTPUT command line to the results output block. If a results block has this set, then it will write output whenever a previous region writes output. The ordering of regions is based on the order in the input file, algorithmic considerations, or by solution control specifications.

Although the USE OUTPUT SCHEDULER command line can also synchronize output between regions, the SYNCHRONIZE OUTPUT command line will synchronize the output with regions where the output frequency is not under the direct control of the Sierra IO system. Examples of this are typically coupled applications where one or more of the codes are not Sierra-based applications such as Alegra and CTH. A results block with SYNCHRONIZE OUTPUT specified will also synchronize its output with the output of the external code.

The SYNCHRONIZE OUTPUT command can be used with other output scheduling commands such as time-based or step-based output specifications.

Shift To Start Time

Syntax: Shift To Start Time
Summary: The shift to start time option allows a user to shift the restart time to the start time of the current region. An example use case would be if a restart time of 0.5 is specified, but the user would like to start the simulation at time 1.0.

Termination Time

Syntax: Termination Time {=} Final_time
Summary: Specify the time to stop outputting results from this output request block.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Final_time	real	–

Timestep Adjustment Interval

Syntax: Timestep Adjustment Interval {=} Nsteps
Summary: Specify the number of steps to ‘look ahead’ and adjust the timestep to ensure that the specified output times or simulation end time will be hit ‘exactly’.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Nsteps	integer	–

Use Dynamic Topology Io

Syntax: Use Dynamic Topology Io
Summary: Specify that the app use IO for dynamic topology modifications where the output files are stored in a single database. Legacy file format for dynamically changing topology results in the creation of multiple files for each output on a mesh modification. This option leverages the ability of netCDF to create mesh groups within a single database and concatenate all mesh files into one. The names of each mesh group are of the form IOSS_MESH_GROUP-??? where ??? is the 1-based output index 1, 2, …, 10, …., 100, … Please note that netCDF has a current limit of 65,536 groups

Use Output Scheduler

Syntax: Use Output Scheduler Timer_name
Summary: Associates a predefined output scheduler with this output block (results, restart, heartbeat, or history).

Parameter	Value	Default
Timer_name	string	–

7.9.4. Results Output

Scope: Average Region, Fuego Region, Input_Output Region, Particle Region
Summary: Describes the location and type of the output stream used for outputting results for the enclosing region.

begin Results Output Label

   Additional Steps {=} List_of_steps...

   Additional Times {=} List_of_times...

   At Step n {increment | interval} {=} m

   At Time Dt1 {increment | interval} {=} Dt2

   Auto Output {all | element | global | nodal} User Defined Variables [ In UserOutputResultsList...  ]

   Auto Output {all | element | global | nodal} Variables

   Component Separator Character {=} Separator

   Database Name {=} StreamName

   Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}

   Edge VariableList...

   Element VariableList...

   Enable Large Ids

   Exclude {=} [ ElementBlockList...  ]

   Exists {=} {abort | add_suffix | append | overwrite}

   Face VariableList...

   Flush Interval {=} Option

   Global VariableList...

   Include {=} [ ElementBlockList...  ]

   Nodal VariableList...

   Node VariableList...

   Nodeset VariableList...

   Output Mesh {=} {exposed surface | refined | unrefined}

   Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}

   Overwrite {=} {false | no | off | on | true | yes}

   Property PropertyName {=} PropertyValue

   Sideset VariableList...

   Start Time {=} Start_time

   Surface VariableList...

   Synchronize Output

   Termination Time {=} Final_time

   Timeseries Name {=} filename

   Timestep Adjustment Interval {=} Nsteps

   Title

   Use Dynamic Topology Io

   Use Output Scheduler Timer_name

   begin Catalyst Label
   end

end Results Output Label

7.9.4.1. Line Commands

Additional Steps

Syntax: Additional Steps {=} List_of_steps…
Summary: Additional simulation steps when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_steps	integer…	–

Additional Times

Syntax: Additional Times {=} List_of_times…
Summary: Additional simulation times when output should occur.

Parameter	Value	Default
{=}	{= \| are \| is}	–
List_of_times	real…	–

At Step

Syntax: At Step n {increment | interval} {=} m
Summary: Specify an output interval in terms of the internal iteration step count. The first step specifies the step count at the beginning of this interval and the second step specifies the output frequency to be used within this interval.

Parameter	Value	Default
n	integer	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
m	integer	–

At Time

Syntax: At Time Dt1 {increment | interval} {=} Dt2
Summary: Specify an output interval in terms of the internal simulation time. The first time specifies the time at the beginning of this time interval and the second time specifies the output frequency to be used within this interval.

Parameter	Value	Default
Dt1	real	–
Option	{increment \| interval}	–
{=}	{= \| are \| is}	–
Dt2	real	–

Auto Output

Syntax: Auto Output {all | element | global | nodal} User Defined Variables [ In UserOutputResultsList… ]
Summary: Allows users to automatically output all user output defined variables for the type requested.

Parameter	Value	Default
auto_output_type_3	{all \| element \| global \| nodal}	–

Auto Output

Syntax: Auto Output {all | element | global | nodal} Variables
Summary: Allows users to automatically output all user output defined variables for the type requested.

Parameter	Value	Default
auto_output_type_3	{all \| element \| global \| nodal}	–

Component Separator Character

Syntax: Component Separator Character {=} Separator
Summary: The separator is the single character used to separate the output variable basename (e.g. “stress”) from the suffices (e.g. “xx”, “yy”) when displaying the names of the individual variable components. For example, the default separator is “_”, which results in names similar to “stress_xx”, “stress_yy”, … “stress_zx”. To eliminate the separator, specify an empty string (“”) or NONE.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Separator	string	–

Database Name

Syntax: Database Name {=} StreamName
Summary: The base name of the database containing the output results. If the filename begins with the ‘/’ character, it is an absolute path; otherwise, the path to the current directory will be prepended to the name. If this line is omitted, then a filename will be created from the basename of the input file with a “.e” suffix appended.

Parameter	Value	Default
{=}	{= \| are \| is}	–
StreamName	string	–

Database Type

Syntax: Database Type {=} {catalyst | catalyst_exodus | cgns | dof | dof_exodus | exodus | exodusii | exonull | generated | genesis | null | parallel_exodus | textmesh}
Summary: The database type/format to be used for the output results.

Parameter	Value	Default
{=}	{= \| are \| is}	–
DatabaseType	{catalyst \| catalyst_exodus \| cgns \| dof \| dof_exodus \| exodus \| exodusii \| exonull \| generated \| genesis \| null \| parallel_exodus \| textmesh}	–

Edge

Syntax: Edge VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”. Edge variables are not supported for all database types.

Parameter	Value	Default
VariableList	string…	–

Element

Syntax: Element VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”

Parameter	Value	Default
VariableList	string…	–

Enable Large Ids

Syntax: Enable Large Ids
Summary: Enable 64 bit entity IDs for output

Exclude

Syntax: Exclude {=} [ ElementBlockList… ]
Summary: Specify that the results file will only contain a subset of the element blocks in the analysis model. The element_block_list lists only the blocks which will not be output to the results database.

Parameter	Value	Default
{=}	{= \| are \| is}	–

Exists

Syntax: Exists {=} {abort | add_suffix | append | overwrite}
Summary: Specify the behavior when creating this database and there is an existing file with the same name. The default behavior is “OVERWRITE” which deletes the existing file and creates a new file of the same name. “APPEND” will (if possible) append the new data to the end of the existing file. “ABORT” will print an error message and end the analysis. “ADD_SUFFIX” will add a -s???? suffix where the ???? is replaced by a sequential number starting at 0002.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{abort \| add_suffix \| append \| overwrite}	–

Face

Syntax: Face VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”. Face variables are not supported for all database types.

Parameter	Value	Default
VariableList	string…	–

Flush Interval

Syntax: Flush Interval {=} Option
Summary: The minimum time interval (in seconds) at which output will be explicitly flushed to disk. The default is 10 seconds.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Option	integer	10

Global

Syntax: Global VariableList…
Summary: Define the global variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line.

Parameter	Value	Default
VariableList	string…	–

Include

Syntax: Include {=} [ ElementBlockList… ]
Summary: Specify that the results file will only contain a subset of the element blocks in the analysis model. The element_block_list lists only the blocks which will be output to the results database.

Parameter	Value	Default
{=}	{= \| are \| is}	–

Nodal

Syntax: Nodal VariableList…
Summary: Define the nodal variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line.

Parameter	Value	Default
VariableList	string…	–

Node

Syntax: Node VariableList…
Summary: Define the nodal variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line.

Parameter	Value	Default
VariableList	string…	–

Nodeset

Syntax: Nodeset VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”. Nodeset variables are not supported for all database types.

Parameter	Value	Default
VariableList	string…	–

Output Mesh

Syntax: Output Mesh {=} {exposed surface | refined | unrefined}
Summary: Use this command to turn on “unrefined” as the output mesh. The default behavior is “refined”, in which field variables are output on the current mesh, which may have been refined (either uniformly or adaptively) or had its topology altered in some way (e.g., dynamic load balancing) with respect to the original mesh read from the input file. By specifying “Output Mesh = unrefined”, all output variables are output only on the original mesh objects read from the input file.

Parameter	Value	Default
{=}	{= \| are \| is}	–
OutputMesh	{exposed surface \| refined \| unrefined}	–

Output On Signal

Syntax: Output On Signal {=} {sigabrt | sigalrm | sigfpe | sighup | sigill | sigint | sigkill | sigpipe | sigquit | sigsegv | sigterm | sigusr1 | sigusr2}
Summary: When the specified signal is raised, the output stream associated with this block will be output.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Signals	{sigabrt \| sigalrm \| sigfpe \| sighup \| sigill \| sigint \| sigkill \| sigpipe \| sigquit \| sigsegv \| sigterm \| sigusr1 \| sigusr2}	–

Overwrite

Syntax: Overwrite {=} {false | no | off | on | true | yes}
Summary: (DEPRECATED, Use EXISTS) Specify whether the database should be overwritten if it exists. The default behavior is to overwrite unless this command is specified in the output block and either off, false, or no is specified.

Parameter	Value	Default
{=}	{= \| is}	–
Option2	{false \| no \| off \| on \| true \| yes}	–

Property

Syntax

Property PropertyName {=} PropertyValue

Summary

Define a database property named “PropertyName” with the value “PropertyValue”. If PropertyValue consists of all digits, it will define an integer property. If PropertyValue is “true” or “yes” or “false” or “no”, it will define a logical property; otherwise it will define a string property. Supported properties are typically database dependent; Current properties are:

COMPRESSION_LEVEL = [0..9] (off)
COMPRESSION_SHUFFLE = true|false|on|off (off)
FILE_TYPE = netcdf4 (forces use of netcdf-4 hdf5-based file) (netcdf3)
INTEGER_SIZE_DB = 4|8 (4)
INTEGER_SIZE_API = 4|8 (4)
REAL_SIZE_DB = 4|8 (8 is default)
LOGGING = true|false|on|off (off)
MAX_NAME_LENGTH = value (32)

Parameter	Value	Default
PropertyName	string	–
{=}	{= \| are \| is}	–
PropertyValue	string	–

Sideset

Syntax: Sideset VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”. Face variables are not supported for all database types.

Parameter	Value	Default
VariableList	string…	–

Start Time

Syntax: Start Time {=} Start_time
Summary: Specify the time to start outputting results from this output request block. This time overrides all ‘at time’ and ‘at step’ specifications.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Start_time	real	–

Surface

Syntax: Surface VariableList…
Summary: Define the variables that should be written to the results database. If “variable” is entered, then its name will be used on the output database. If “variable as db_name” is entered, then “db_name” will be the name used on the database for the internal variable “variable”. Multiple “variable” or “variable as db_name” entries are allowed on the same line. The entities that this variable are written to can also be limited or specified with “exclude list_of_entities” or “include list_of_entities”. Face variables are not supported for all database types.

Parameter	Value	Default
VariableList	string…	–

Synchronize Output

Syntax

Synchronize Output

Summary

In an analysis with multiple regions, it is sometimes desirable to synchronize the output of results data between the regions. This can be done by adding the SYNCHRONIZE OUTPUT command line to the results output block. If a results block has this set, then it will write output whenever a previous region writes output. The ordering of regions is based on the order in the input file, algorithmic considerations, or by solution control specifications.

Although the USE OUTPUT SCHEDULER command line can also synchronize output between regions, the SYNCHRONIZE OUTPUT command line will synchronize the output with regions where the output frequency is not under the direct control of the Sierra IO system. Examples of this are typically coupled applications where one or more of the codes are not Sierra-based applications such as Alegra and CTH. A results block with SYNCHRONIZE OUTPUT specified will also synchronize its output with the output of the external code.

The SYNCHRONIZE OUTPUT command can be used with other output scheduling commands such as time-based or step-based output specifications.

Termination Time

Syntax: Termination Time {=} Final_time
Summary: Specify the time to stop outputting results from this output request block.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Final_time	real	–

Timeseries Name

Syntax: Timeseries Name {=} filename
Summary: Optionally specify a filename for a timeseries file that outputs the root database filename in the order that they are written. This is useful when running on large numbers of processors with many mesh-mods that cause simple disk operations to hang.

Parameter	Value	Default
{=}	{= \| are \| is}	–
filename	string	–

Timestep Adjustment Interval

Syntax: Timestep Adjustment Interval {=} Nsteps
Summary: Specify the number of steps to ‘look ahead’ and adjust the timestep to ensure that the specified output times or simulation end time will be hit ‘exactly’.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Nsteps	integer	–

Title

Syntax: Title
Summary: Specify the title to be used for this specific output block.

Use Dynamic Topology Io

Syntax: Use Dynamic Topology Io
Summary: Specify that the app use IO for dynamic topology modifications where the output files are stored in a single database. Legacy file format for dynamically changing topology results in the creation of multiple files for each output on a mesh modification. This option leverages the ability of netCDF to create mesh groups within a single database and concatenate all mesh files into one. The names of each mesh group are of the form IOSS_MESH_GROUP-??? where ??? is the 1-based output index 1, 2, …, 10, …., 100, … Please note that netCDF has a current limit of 65,536 groups

Use Output Scheduler

Syntax: Use Output Scheduler Timer_name
Summary: Associates a predefined output scheduler with this output block (results, restart, heartbeat, or history).

Parameter	Value	Default
Timer_name	string	–

7.9.5. Solution Options

Scope: Average Region, Fuego Region
Summary: Specify information regarding the governing equations to be solved.

begin Solution Options OptionsName

   Activate Acoustic Compressibility Algorithm

   Activate Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}

   Activate Full Surface Cvfem Gradient Operator For Muscl Scheme

   Activate Lighthill Tensor Postprocessing

   Activate Species Enthalpy Calculations

   Activate Viscous Dissipation Source Term

   Compute Steady Solution Using Pseudo Transient Method

   Coordinate System {=} {2d | 3d | xaxi | yaxi}

   First Order Upwind Factor {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Fix Pressure To FixedPressure At A Single Node

   Hybrid Upwind Factor {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Hybrid Upwind Method {=} {blending | tanh} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Hybrid Upwind Shift {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Hybrid Upwind Width {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Include Continuity Residual Term [ With Diagnostics  ]

   Lighthill Tensor Smoothing Iterations {=} Number

   Maximum Number Of Continuity_Momentum Nonlinear Iterations {=} Number

   Maximum Number Of Energy_Species Nonlinear Iterations {=} Number

   Maximum Number Of Gas_Solid_Momentum Nonlinear Iterations {=} Number

   Maximum Number Of Kepsilon Nonlinear Iterations {=} Number

   Maximum Number Of Komega Nonlinear Iterations {=} Number

   Maximum Number Of Ksgs Nonlinear Iterations {=} Number

   Maximum Number Of Mixture Fraction Nonlinear Iterations {=} Number

   Maximum Number Of Nonlinear Iterations {=} Number

   Maximum Number Of Solid Phase Nonlinear Iterations {=} Number

   Maximum Number Of Soot Nuclei Nonlinear Iterations {=} Number

   Maximum Number Of Species Nonlinear Iterations {=} Number

   Maximum Number Of Species_Product Nonlinear Iterations {=} Number

   Maximum Number Of V2F Nonlinear Iterations {=} Number

   Maximum Wall Time {=} WallTime Hours

   Minimum Number Of Nonlinear Iterations {=} Number

   Nonlinear Residual Norm Tolerance {=} Tolerance [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Nonlinear Stabilization Method {=} {commutation_error | none | pointwise_residual_error} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Omit Density Time Derivative In Continuity Equation [ For OmitSteps Steps And Blend In Over BlendSteps Steps  ]

   Output Nonlinear Residual Field For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} As ResName [ On Output Block BlockName  ]

   Periodic Constant Momentum Body Source Term {=} ConstSrc1 ConstSrc2 ConstSrc3

   Progress Variable Source Evaluation Time {=} {latest | presolve}

   Projection Method {=} {fourth_order | second_order | stabilized | zeroth_order} Smoothing [ With {characteristic | momentum | timestep} Scaling  ]

   Randomize Pressure

   Skip Pressure Update If Continuity Solve Fails

   Source Term Function {=} FuncStr For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ VariableName  ]

   Source Term Subroutine {=} Subroutine For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ VariableName  ]

   Stop Simulation If Peak Velocity Exceeds MaxVel

   Under Relax {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} By Urf [ With Implicit Term  ]

   Under Relax Momentum By Urf

   Under Relax Pressure By Urf

   Under Relax Solid_Momentum By Urf

   Under Relax Temperature_Extraction By Urf

   Upwind Limiter {=} {minmod | none | superbee | van_albada | van_leer} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Upwind Method {=} {lps | muscl | upw} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   Use Equation Solver SolverName For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}

   Use External Continuity Source

   Use External Energy Source

   Use External Mixture_Fraction Source

   Use External Momentum Source

   Use External Soot_Mass_Fraction Source

   Use External Species Source

   Use Lumped Velocity Density Interpolation

   Use Radiation Source From External Region [ Using Classic Linearization  ]

   Use Shifted Density Iteration

   Use Skew Symmetric Central Operator [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}  ]

   begin Acoustic Transfer Output DefinitionName
   end

   begin Beam Radiation Boundary Specification DefinitionName
   end

   begin Buoyancy Model Specification BuoyModelName
   end

   begin Edc Model Specification EdcSpecName
   end

   begin Mesh Motion Specification DefinitionName
   end

   begin Multiphase Model Specification DefinitionName
   end

   begin Point Source DefinitionName
   end

   begin Rad Transport Spectral Model Specification DefinitionName
   end

   begin Radiation Transport Equation Model Specification RadModelName
   end

   begin Time Integration Specification TimeIntSpecName
   end

   begin Turbulence Model Specification TurbSpecName
   end

   begin Vof Model Specification DefinitionName
   end

end Solution Options OptionsName

7.9.5.1. Line Commands

Activate Acoustic Compressibility Algorithm

Syntax

Activate Acoustic Compressibility Algorithm

Summary

Variable thermodynamic pressure

Description

This option will allow for closed system pressurization either through heat-up or inflow of fluid.

The algorithm will add the substantial derivative of pressure, $\frac{\partial p}{\partial t} + u_j \frac{\partial p}{\partial x_j}$ , to the laminar or turbulent enthalpy transport equation and to the laminar temperature transport equation. Additionally, the viscous work term $u_i \frac{\partial \tau_{ij}}{\partial x_j}$ will be added to the turbulent enthalpy equation. An implicit term in the continuity solve is added through the time density derivative. As such, Cantera support is required. The convective terms within the continuity solve are neglected.

Caveats for this model:

The Cantera material model evaluator must be used.

2) The initial pressure and any boundary condition pressures must be specified with respect to the datum pressure.

If a zero datum pressure is specified, then all initial and boundary pressures will be in absolute units. If this is a coupled structural simulation, then the surface traction due to this pressure will need to be counteracted with a load on the “back side” that is equivalent to the ambient pressure in absolute units.

If a non-zero datum pressure is specified, then all initial and boundary pressures will be in relative units with respect to this datum. Pressure can then be thought of as a gauge pressure with respect to the datum. The “back side” load in structural simulations must be set accordingly. (For example, if the datum is set equal to the external ambient pressure, 1 atm, and the initial pressure is set to zero, then the initial surface traction force due to pressure will be zero and no “back side” load due to the ambient pressure should be specified.)

Activate Equation

Syntax: Activate Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}
Summary: Activate the specified equation.

Parameter	Value	Default
Equations	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–

Activate Full Surface Cvfem Gradient Operator For Muscl Scheme

Syntax: Activate Full Surface Cvfem Gradient Operator For Muscl Scheme
Summary: Use full stencil for gradient used in MUSCL convection operator
Description: The default gradient operator for the MUSCL scheme is the edge-based stencil. This option keeps integration points at the subcontrol surface points.

Activate Lighthill Tensor Postprocessing

Syntax: Activate Lighthill Tensor Postprocessing
Summary: Postprocesses the nodal divergence of the Lighthill tensor
Description: This calculates the nodal divergence of the Lighthill tensor, used for acoustic analysis.

Activate Species Enthalpy Calculations

Syntax: Activate Species Enthalpy Calculations
Summary: Enables calculation of species enthalpy
Description: This forces the calculation of species enthalpy, needed primarily for coupled Fuego-Aria problems.

Activate Viscous Dissipation Source Term

Syntax: Activate Viscous Dissipation Source Term
Summary: Add viscous dissipation source term
Description: For low speed viscous dissipation effects, this source term will provide the viscous work source term in the static enthalpy equation. This source term is a subset of the full acoustically compressible source term option, however, the substantial pressure derivative is omitted.

Compute Steady Solution Using Pseudo Transient Method

Syntax

Compute Steady Solution Using Pseudo Transient Method

Summary

Compute a steady-state solution using the pseudo-transient method (time march to steady solution).

Description

The solution will march forward in time until either the stopping time is reached or the steady convergence criterion is met. Convergence to steady state is detected when all equations meet their nonlinear residual norm tolerances after the first nonlinear iteration, since this will only occur as the solution stops changing between time steps. The nonlinear residual norm tolerances should be set small enough to prevent false positives. Also make sure the simulation time is set to be fairly large, to prevent a premature end to the simulation before convergence is achieved.

If you are using solution control, then you also need to test for a region parameter to stop the simulation. In your PARAMETERS FOR TRANSIENT solution control block, add the line (assuming your Fuego region is called fuego_region):

CONVERGED WHEN "fuego_region.REGION_STEADY_STATE == 1"

Coordinate System

Syntax: Coordinate System {=} {2d | 3d | xaxi | yaxi}
Summary: Specify the coordinate system.

Parameter	Value	Default
{=}	{= \| are \| is}	–
CoordSys	{2d \| 3d \| xaxi \| yaxi}	3D

First Order Upwind Factor

Syntax

First Order Upwind Factor {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

First-order upwind factor, $0 \lt x \lt 1$

Description

This value specifies the explicit upwind blending between pure upwind and the chosen convection operator, e.g., UPW*(firstOrderUpwind) + (1-firstOrderUpwind)*(blendedUpwindCentral).

where UPW is the pure first order upwind value and blendedUpwindCentral is a blend between the selected upwind method and central difference operator based on the local cell Peclet number (see Hybrid Upwind Factor line command). The value can be a time dependent string function.

Values for individual equation sets may be set using optional token. Using both (in either order):

FIRST ORDER UPWIND FACTOR = String
FIRST ORDER UPWIND FACTOR = String FOR EQUATION Equations

Will result in the particular equation set to specified value while all others set to general value.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	“string”	1.0

Fix Pressure To

Syntax: Fix Pressure To FixedPressure At A Single Node
Summary: Sets a dirichlet for pressure at a single arbitrary node. This is required for a well posed pressure equation if none of the boundaries specify pressure (e.g. open).

Parameter	Value	Default
FixedPressure	real	0.0

Hybrid Upwind Factor

Syntax

Hybrid Upwind Factor {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Hybrid upwinding factor.

Description

The upwind schemes are blended with a centered scheme. The HYBRID UPWIND FACTOR is a multiplier against the cell Peclet number used in the switching scheme (see First Order Upwind Factor line command).

A HYBRID UPWIND FACTOR = 0.0 results in all centered.
A HYBRID UPWIND FACTOR = 1.0 results in default hybrid.
A HYBRID UPWIND FACTOR >> 1.0 results in all upwind.

Values for individual equation sets may be set using optional token. Using both (in either order):

HYBRID UPWIND FACTOR = String
HYBRID UPWIND FACTOR = String FOR EQUATION Equations

Will result in the particular equation set to specified value while all others set to general value. The value can be specified as a time dependent string function or a constant.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	“string”	1.0

Hybrid Upwind Method

Syntax

Hybrid Upwind Method {=} {blending | tanh} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Hybriding method between central and upwind using Peclet number

Description

BLENDING and TANH approaches are currently supported.

Function $\chi$ determines the ratio between user-chosen upwind ( $\chi$ ) and central (1- $\chi$ ) operators. The need for an upwind operator is affected by cell-Peclet number.

BLENDING uses HYBRID UPWIND FACTOR ( $\zeta$ ) and the function is, $\chi = \frac{(\zeta Pe)^2}{5+(\zeta Pe)^2}$ .

TAHH follows hyperbolic tangent profile between $\chi$ and Pe. It uses shift p (HYBRID UPWIND SHIFT) and width w (HYBRID UPWIND WIDTH) parameters as, $\chi = \frac{1}{2}[1+tanh(\frac{Pe-p}{w})]$ . Tanh is centered ( $\chi=0.5$ ) when Peclet number is at the shifting factor p. Width determines how fast $\chi$ changes with Peclet number as follows:

$\chi=$ 0.5 at Pe=p.
$\chi=$ 0.8808 and 0.1192 at Pe=p+w and p-w.
$\chi=$ 0.9820 and 0.0180 at Pe=p+2w and p-2w.
$\chi=$ 0.9975 and 0.0025 at Pe=p+3w and p-3w.
$\chi=$ 0.9997 and 0.0003 at Pe=p+4w and p-4w.

TANH allows users to effectively remove upwind contribution for lower Pe. In the other extreme, one can enforce user-chosen upwind at all Pe if p < 0.0 and w << 1.0 (ex> p=-1.0, w=1e-10).

Parameter	Value	Default
{=}	{= \| are \| is}	–
HybridMethod	{blending \| tanh}	BLENDING

Hybrid Upwind Shift

Syntax: Hybrid Upwind Shift {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]
Summary: Shifting factor for TANH hybrid approach. Can be specified as a time dependent string function or a constant.
Description: (see HYBRID UPWIND METHOD description)

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	“string”	0.0

Hybrid Upwind Width

Syntax: Hybrid Upwind Width {=} Value [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]
Summary: Width factor for TANH hybrid approach
Description: Minimum value for this parameter is 1e-10. (see HYBRID UPWIND METHOD description) Can be specified as a time dependent string function or a constant value.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	“string”	1.0

Include Continuity Residual Term

Syntax

Include Continuity Residual Term [ With Diagnostics ]

Summary

Include the continuity residual term in transport equations

Description

Continuity is not exactly satisfied during the momentum solve for variable density flows since the mass flux is lagged while the density is updated with new properties. Including the continuity error in momentum can keep the momentum prediction better behaved. The residual should be on the order of the linear solver tolerance for other equations, but including the term can also make the other solves more robust to a bad continuity solve.

This term is always included when using VOF or a deforming mesh.

Lighthill Tensor Smoothing Iterations

Syntax: Lighthill Tensor Smoothing Iterations {=} Number
Summary: Number of smoothing iterations for the divergence of the Lighthill tensor.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	–

Maximum Number Of Continuity_Momentum Nonlinear Iterations

Syntax: Maximum Number Of Continuity_Momentum Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the momentum/continuity solve.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Energy_Species Nonlinear Iterations

Syntax: Maximum Number Of Energy_Species Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the energy-species grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Gas_Solid_Momentum Nonlinear Iterations

Syntax: Maximum Number Of Gas_Solid_Momentum Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the gas/solid momentum sets of equations.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Kepsilon Nonlinear Iterations

Syntax: Maximum Number Of Kepsilon Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the k-epsilon turbulence model equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Komega Nonlinear Iterations

Syntax: Maximum Number Of Komega Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the k-omega turbulence model equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Ksgs Nonlinear Iterations

Syntax: Maximum Number Of Ksgs Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the ksgs turbulence model equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Mixture Fraction Nonlinear Iterations

Syntax: Maximum Number Of Mixture Fraction Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the mixture fraction equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Nonlinear Iterations

Syntax: Maximum Number Of Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the time step of the Fuego region.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Solid Phase Nonlinear Iterations

Syntax: Maximum Number Of Solid Phase Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the solid momentum/continuity sets of equations.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Soot Nuclei Nonlinear Iterations

Syntax: Maximum Number Of Soot Nuclei Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the soot nuclei equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Species Nonlinear Iterations

Syntax: Maximum Number Of Species Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations for the species equations. If the EDC product transport feature is active, then the SPECIES_PRODUCT nonlinear iteration count should be set instead.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of Species_Product Nonlinear Iterations

Syntax: Maximum Number Of Species_Product Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the Species/EDC_Product grouping. This is only used if the EDC model is active and the EDC product transport feature is being used.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Number Of V2F Nonlinear Iterations

Syntax: Maximum Number Of V2F Nonlinear Iterations {=} Number
Summary: Maximum number of nonlinear iterations to take within the v2f turbulence model equations grouping.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Maximum Wall Time

Syntax: Maximum Wall Time {=} WallTime Hours
Summary: Specify a maximum wall time to let the simulation end gracefully and output before slurm kills it.

Parameter	Value	Default
{=}	{= \| are \| is}	–
WallTime	real	Infinite

Minimum Number Of Nonlinear Iterations

Syntax: Minimum Number Of Nonlinear Iterations {=} Number
Summary: Minimum number of nonlinear iterations to take within the time step of the Fuego region.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Number	integer	1

Nonlinear Residual Norm Tolerance

Syntax

Nonlinear Residual Norm Tolerance {=} Tolerance [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Nonlinear convergence tolerance within a time step in the Fuego region.

Values for individual equation sets may be set using the optional token. Using both (in either order):

NONLINEAR RESIDUAL NORM TOLERANCE = {Real}
NONLINEAR RESIDUAL NORM TOLERANCE = {Real} FOR EQUATION {Equations}

Will result in the particular equation set to specified value while all others set to general value.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Tolerance	real	1.0e-15

Nonlinear Stabilization Method

Syntax

Nonlinear Stabilization Method {=} {commutation_error | none | pointwise_residual_error} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Specify a artificial viscosity stabilization; default is NONE.

Description

Values for individual equation sets may be set using optional token. Using both (in either order):

NSO METHOD = NSOMethod
NSO METHOD = NSOMethod FOR EQUATION Equations

Will result in the particular equation set to specified value while all others set to general value.

Parameter	Value	Default
{=}	{= \| are \| is}	–
NSOMethod	{commutation_error \| none \| pointwise_residual_error}	NO_NSO

Omit Density Time Derivative In Continuity Equation

Syntax

Omit Density Time Derivative In Continuity Equation [ For OmitSteps Steps And Blend In Over BlendSteps Steps ]

Summary

Remove density time derivative in continuity equation

Description

Remove the density time derivative from the continuity equation. This feature is required for closed boundary flows with accumulation.

The optional arguments let you omit it for a certain number of timesteps at the start of the simulation, then gradually include it over a number of steps.

Output Nonlinear Residual Field For Equation

Syntax: Output Nonlinear Residual Field For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} As ResName [ On Output Block BlockName ]
Summary: Generates output of nonlinear residuals for the requested equation.
Description: Provide nonlinear residual for output for specified equation. If the optional output block name is specified, then the residual will only be written to that output block.

Parameter	Value	Default
Equations	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–
ResName	string	–

Periodic Constant Momentum Body Source Term

Syntax: Periodic Constant Momentum Body Source Term {=} ConstSrc1 ConstSrc2 ConstSrc3
Summary: Add constant body force due to periodic config
Description: For periodic BCS, commonly a constant body force is applied to drive the flow. This line command allows one to provide a constant body force in three dimensions. If more complex sources are needed, the user sub source term procedure is required.

Parameter	Value	Default
{=}	{= \| are \| is}	–
ConstSrc	real1 real2 real3	–

Progress Variable Source Evaluation Time

Syntax: Progress Variable Source Evaluation Time {=} {latest | presolve}
Summary: Evaluation point for sequences of interdependent progress variable source terms. Either the most recently nonlinear update is used in the order in which the progress variables are solved, or the progress variable source terms are evaluated together presolve.

Parameter	Value	Default
{=}	{= \| are \| is}	–
EvalTime	{latest \| presolve}	–

Projection Method

Syntax: Projection Method {=} {fourth_order | second_order | stabilized | zeroth_order} Smoothing [ With {characteristic | momentum | timestep} Scaling ]
Summary: Specify choice of projection method.
Description: The smoothing choice may include zeroth, second, or fourth order. No smoothing (zeroth) may allow pressure-velocity decoupling.

The scaling term may be specified. This scaling term is related to the factorization approximation to the inverse of the momentum matrix.

Time step scaling may show results that are sensitive to the chosen simulation dt at coarse meshes. This error should vanish as the pressure field approached a linear shape, or refinement is performed. Note that characteristic scaling also has the same error, however, its manifestation is less obvious.

The stabilized option uses a fourth order smoothing term and characteristic scaling along with an additional dt stabilizing term.

In general, the stabilized and “fourth order smoothing” timestep scaling allows for larger time steps. Characteristic scaling seems to limit CFL to below unity, presumably due to stability loss during nodal projection, i.e., splitting error is $(I - \tau A) G (\Delta P)$ .

“Momentum Scaling”, uses the diagonal of the momentum equation as the scaling term. While the leading order term with this method will be similar to the timestep scaling scheme, it can sometimes offer better stability since it also includes effects from the other terms in the momentum equation.

Parameter	Value	Default
{=}	{= \| are \| is}	–
ProjectionMethod	{fourth_order \| second_order \| stabilized \| zeroth_order}	–

Randomize Pressure

Syntax: Randomize Pressure
Summary: Set a random pressure field for initial guess
Description: Randomize the initial guess to the linear solve for pressure. The randomization is imposed after the nonlinear residual is computed.

Skip Pressure Update If Continuity Solve Fails

Syntax

Skip Pressure Update If Continuity Solve Fails

Summary

Do not update the pressure field or mdot if the continuity solve fails

Description

If the continuity solve fails the resulting pressure delta may be large or non-physical. Activating this option skips the pressure update and mdot update when the solver fails. Repeated solver failures should be watched for in the log file.

This is a beta feature.

Source Term Function

Syntax

Source Term Function {=} FuncStr For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ VariableName ]

Summary

Source term string function to use for the given equation. Registered variables with aliases include time (t), spatial coordinates (x,y,z), velocity (u,v,w), density (rho), and pressure (p). Additionally, any valid global variable or nodal variable can be used with its full name. Vector variables, like mass fraction, must be indexed numerically (e.g. “mass_fraction[3]”)

The function string must be enclosed in quotes if it has spaces or commas. For example: Source Term Function for x_momentum = “min(1, 0.1*t)”

Parameter	Value	Default
{=}	{= \| are \| is}	–
FuncStr	“string”	–
Equation	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–

Source Term Subroutine

Syntax: Source Term Subroutine {=} Subroutine For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ VariableName ]
Summary: Source term user subroutine for the given equation. This is often useful in verification studies where one wishes to use a manufactured solution and must provide source terms for various governing equations.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Subroutine	string	–
Equations	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–

Stop Simulation If Peak Velocity Exceeds

Syntax

Stop Simulation If Peak Velocity Exceeds MaxVel

Summary

Abort the simulation if velocities get too large.

Description

By default Fuego will continue time stepping as the simulation diverges and will go until velocities overflow or solvers start returning NaN or Inf.

If you want it to stop sooner than that, you can set a peak velocity magnitude to abort at.

Parameter	Value	Default
MaxVel	real	infinity

Under Relax

Syntax

Under Relax {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} By Urf [ With Implicit Term ]

Summary

Under relaxation factor for the given equation.

Description

Implicit relaxation is applied to the momentum equations. Explicit relaxation is applied to the pressure update. Transport equations are relaxed explicitly unless the “WITH IMPLICI TERM” option is used.

Under-relaxation can be a constant value or a function of time (t). If the function used has spaces or commas, it should be enclosed in quotes. The value will be internally clipped between 1e-6 and 1.

Parameter	Value	Default
Equations	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–
Urf	“string”	1.0

Under Relax Momentum By

Syntax

Under Relax Momentum By Urf

Summary

Under relaxation factor for the momentum equations.

Under-relaxation can be a constant value or a function of time (t). If the function used has spaces or commas, it should be enclosed in quotes. The value will be internally clipped between 1e-6 and 1.

Parameter	Value	Default
Urf	“string”	–

Under Relax Pressure By

Syntax

Under Relax Pressure By Urf

Summary

Under relaxation factor for the pressure. This is equivalent to specifying an URF on continuity, and is provided for backward compatibility.

Under-relaxation can be a constant value or a function of time (t). If the function used has spaces or commas, it should be enclosed in quotes. The value will be internally clipped between 1e-6 and 1.

Parameter	Value	Default
Urf	“string”	–

Under Relax Solid_Momentum By

Syntax

Under Relax Solid_Momentum By Urf

Summary

Under relaxation factor for the solid-phase momentum equations.

Under-relaxation can be a constant value or a function of time (t). If the function used has spaces or commas, it should be enclosed in quotes. The value will be internally clipped between 1e-6 and 1.

Parameter	Value	Default
Urf	“string”	–

Under Relax Temperature_Extraction By

Syntax: Under Relax Temperature_Extraction By Urf
Summary: Under relaxation factor for the temperature extraction from enthalpy
Description: Relax the temperature computed from the enthalpy. This gives a temperature that is not entirely consistent with the current state (composition and enthalpy), and will destroy time-accuracy unless sufficient Picard loops are taken. However, it may be useful for steady-state computations where species and energy equations are not being coupled strongly or solved accurately.

Under-relaxation can be a constant value or a function of time (t). If the function used has spaces or commas, it should be enclosed in quotes. The value will be internally clipped between 1e-6 and 1.

Parameter	Value	Default
Urf	“string”	–

Upwind Limiter

Syntax

Upwind Limiter {=} {minmod | none | superbee | van_albada | van_leer} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Specify a limiter for convection operator; default is SUPERBEE.

Description

Limiter functions are valid only for the MUSCL scheme.

Values for individual equation sets may be set using optional token. Using both (in either order):

UPWIND LIMITER = UpwindLimiter
UPWIND LIMITER = UpwindLimiter FOR EQUATION Equations

Will result in the particular equation set to specified value while all others set to general value.

Note: Rotational invariance of the code is not expected while using a limiter function.

Parameter	Value	Default
{=}	{= \| are \| is}	–
UpwindLimiter	{minmod \| none \| superbee \| van_albada \| van_leer}	SUPERBEE

Upwind Method

Syntax

Upwind Method {=} {lps | muscl | upw} [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

Upwind method for convective terms

Description

All methods are hybrid in the sense that a centered scheme is blended based on the local Peclet number.

Values for individual equation sets may be set using optional token. Using both (in either order):

UPWIND METHOD = UpwindMethod
UPWIND METHOD = UpwindMethod FOR EQUATION Equations

Will result in the particular equation set to specified value while all others set to general value.

Parameter	Value	Default
{=}	{= \| are \| is}	–
UpwindMethod	{lps \| muscl \| upw}	LPS

Use Equation Solver

Syntax

Use Equation Solver SolverName For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum}

Summary

Link an equation solver to an equation set.

Description

For example, if a solver block “scalar” was created using the Tpetra package, e.g., BEGIN TPETRA EQUATION SOLVER scalar and the equation set was the u-component of momentum then the line command would be as follows: USE EQUATION SOLVER scalar FOR EQUATION X-Momentum.

This command can be omitted, and a default solver will be assigned (either the HIGH_ASPECT_CONTINUITY or SCALAR_TRANSPORT preset solvers). The default continuity solver is GMRES with the MueLu preconditioner and the default scalar transport solver is GMRES with the SGS preconditioner.

Parameter	Value	Default
SolverName	string	–
Equations	{conserved_enthalpy \| continuity \| edc_product \| enthalpy \| mixture_fraction \| nuclei \| progress_variable \| scalar_variance \| second_mixture_fraction \| solid_volume_fraction \| soot \| species \| temperature \| turbulent_dissipation \| turbulent_frequency \| turbulent_helmholtz_function \| turbulent_kinetic_energy \| turbulent_v2 \| volume_of_fluid \| x_momentum \| x_solid_momentum \| y_momentum \| y_solid_momentum \| z_momentum \| z_solid_momentum}	–

Use External Continuity Source

Syntax: Use External Continuity Source
Summary: Add external species source term from a transfer
Description: Add source terms to the continuity equation from a nodal field transferred to this region, e.g. from a Fuego particle region. The field continuity_source will be added to the RHS of the continuity equation; this fields should have units of rate-of-change of mass per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use External Energy Source

Syntax: Use External Energy Source
Summary: Add external energy source term from a transfer
Description: Add source terms to the temperature or enthalpy equations from a nodal field transferred to this region, e.g. from a Fuego particle region. The field energy_source will be added to the RHS of the energy equation; this fields should have units of rate-of-change of energy per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use External Mixture_Fraction Source

Syntax: Use External Mixture_Fraction Source
Summary: Add external species source term from a transfer
Description: Add source terms to the mixture fraction equation from a nodal field transferred to this region, e.g. from a Fuego particle region. The field mixture_fraction_source will be added to the RHS of the mixture fraction equation; this fields should have units of rate-of-change of mass per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use External Momentum Source

Syntax: Use External Momentum Source
Summary: Add external momentum source terms from a transfer
Description: Add source terms to the momentum equations from a nodal field transferred to this region, e.g. from a Fuego particle region. The fields x_momentum_source, y_momentum_source, and z_momentum source will be added to the RHS of the momentum equations; these fields should have units of rate-of-change of momentum per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use External Soot_Mass_Fraction Source

Syntax: Use External Soot_Mass_Fraction Source
Summary: Add external soot source term from a transfer
Description: Add source terms to the soot mass fraction equation from a nodal field transferred to this region, e.g. from a Fuego particle region. The field soot_mass_fraction_source will be added to the RHS of the soot mass fraction equation; this fields should have units of rate-of-change of mass per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use External Species Source

Syntax: Use External Species Source
Summary: Add external species source term from a transfer
Description: Add source terms to the species equations from a nodal field transferred to this region, e.g. from a Fuego particle region. The vector field species_source will be added to the RHS of the species equation; this fields should have units of rate-of-change of mass of species i per volume, so that multiplication by the control volume gives the correct source term. The transfer operation should send to the variables at state “none”.

Use Lumped Velocity Density Interpolation

Syntax: Use Lumped Velocity Density Interpolation
Summary: Interpolate the density-velocity product
Description: By default the continuity equation interpolates velocity and density separately to sub-control surfaces. This option interpolates the product of density times velocity instead.

Use Radiation Source From External Region

Syntax

Use Radiation Source From External Region [ Using Classic Linearization ]

Summary

Add in a source term from participating-media radiation which comes from another region through a transfer.

The USING CLASSIC LINEARIZATION optional argument is no longer used or needed, and will be removed in a future release.

Use Shifted Density Iteration

Syntax

Use Shifted Density Iteration

Summary

Use a lagged density in the momentum solve but an updated density in the velocity projection

Description

Use a lagged density for momentum solve relative to the velocity projection similar to https://doi.org/10.1016/j.jcp.2012.01.027

This is a beta feature.

Use Skew Symmetric Central Operator

Syntax

Use Skew Symmetric Central Operator [ For Equation {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} ]

Summary

The blended central operator will be skew symmetric, default is ${\bf false}$ .

Description

The convection operator is always blended with pure central (see hybrid factor description). For the CVFEM methodology, there is a balance between stability and accuracy. Dotting the momentum equation with velocity and summing yields the kinetic energy equation. If the convection operator is skew symmetric, than this dot product leaves something that is perfectly zero. This means that there can be no generation of kinetic energy and simulations can remain stable.

The full CVFEM stencil (27-pt on a hex mesh) is not skew symmetric. Therefore, in cases where one uses pure central (by specifying a hybrid factor of unity) there can be issues - especially on coarse meshes.