# 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, , to the laminar or turbulent enthalpy transport equation and to the laminar temperature transport equation. Additionally, the viscous work term 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:

  1. 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,

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

  BLENDING uses HYBRID UPWIND FACTOR () and the function is, .

  TAHH follows hyperbolic tangent profile between and Pe. It uses shift p (HYBRID UPWIND SHIFT) and width w (HYBRID UPWIND WIDTH) parameters as, . Tanh is centered () when Peclet number is at the shifting factor p. Width determines how fast changes with Peclet number as follows:

  - 0.5 at Pe=p.

  - 0.8808 and 0.1192 at Pe=p+w and p-w.

  - 0.9820 and 0.0180 at Pe=p+2w and p-2w.

  - 0.9975 and 0.0025 at Pe=p+3w and p-3w.

  - 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 .

  > “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 .

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.