cfx command language

CFX-Post RetraceMasterContents

MasterIndex

Help OnHelp

CFX-Post

CFX Command Language

• Overview of the CFX Command Language (CCL) p. 164

• CCL Syntax (p. 165)

• Object Creation and Deletion (p. 172)

• CFX Expression Language (CEL) (p. 173)

63 CFX-5.5.1

CFX-PostAdvanced

RetraceMasterContents

MasterIndex

Help OnHelp

Overview of the CFX Command Language (CCL)

The CFX Command Language (CCL) is the internal communicationand command language of CFX-Post. It is a simple language that canbe used to create objects or perform actions in the Post-processor. AllCCL statements can be classified into one of three categories:

1. Object and parameter definitions.

2. Actions.

3. Power Syntax.

Object and parameter definitions are discussed in Object Creationand Deletion (p. 172 in CFX-Post) . A list of all objects and parametersthat can be used in CFX-Post can be found in CCL Details (p. 229 inCFX-Post) .

CCL actions are commands which perform a specific task (e.g. readinga Session file). These commands are discussed in Command Actions(p. 185 in CFX-Post) .

CCL supports programming through Power Syntax. This utilises thePerl programming language to allow loops, logic and custom macros(subroutines). Power Syntax allows Perl commands to be embeddedinto CCL to achieve powerful quantitative Post-processing. Details canbe found in Power Syntax (p. 209 in CFX-Post) .

State and Session files contain object definitions using CCL. In additionSession files can contain CCL action commands. The CCL written tothese files can be viewed and modified in a text editor. You can alsouse a text editor to create your own Session and State files to read intoCFX-Post using CCL.

Advanced users can interact with CFX-Post directly through CCL byentering it in the Command Editor window (see Command Editor(p. 157 in CFX-Post) ) or by running CFX-Post in Line Interface mode(see Line Interface Mode (p. 221 in CFX-Post) for details).

Details of the CCL syntax are discussed on the following pages.

Page 164 Overview of the CFX Command Language (CCL) CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

CCL Syntax

Basic Terminology

The following is an example of a CCL object to define an isosurface.

ISOSURFACE: Iso1Variable = PressureValue = 15000 [Pa]Colour = 1,0,0Transparency = 0.5

END

• ISOSURFACE is an object type

• Iso1 is an object name

• “Variable = Pressure ” is a parameter

• Variable is a parameter name

• Pressure is a parameter value

• If the object type ISOSURFACEdoes not need a name it is called asingleton object. Only one object of a given singleton type can exist.

The Data Hierarchy

Data is entered via parameters, these are grouped into objects whichare stored in a tree structure.

OBJECT1: object namename1 = valuename2 = value

END

Objects and parameters may be placed in any order, provided that theinformation is set prior to being used further down the file. If data is setin one place and modified in another the latter definition overrides thefirst.

In CFX-Post, all object definitions are only one object level deep (i.e.Objects contain parameters, but not other objects).

Page 165 CCL Syntax CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

Simple Syntax DetailsThe following applies to any line that is not a Power Syntax or Actionline, i.e. does not start with a “!” or “>”.

Case Sensitivity

Everything in the file is sensitive to case.

Case sensitivity is not ideal for users typing in many long parameternames, but it is essential for bringing the CFX Expression Language(CEL) into CCL. This is because some names used to define CCLobjects (such as Fluids, Materials and Additional Variables) are usedto construct corresponding CEL names. Case sensitive CEL nameshave been in use since CFX-5.2 (e.g. t = time and T = temperature).

For simplicity and consistency, we recommend the followingconvention is used in the standard code and its documentation:

• singletons and object types use upper case only

• parameter names , and pre-defined object names , are mixed case.We try to follow the following conventions: (1) Major words start withan upper case letter, while minor words such as prepositions andconjunctions are left in lower case, e.g “Mass Flow in” (2) case ispreserved for familiar names, e.g. for variables “k” or “r”, or forabbreviation “RNG”.

• user object names conventions are left to the user to choose.

CCL Names Definition

Names of singletons, types of object, names of objects, and names ofparameters all follow the same rules:

• In simple syntax, a CCL name must be at least one character. Thisfirst character must be alphabetic; there may be any number ofsubsequent characters and these can be alphabetic, numeric,space or tab.

• The effect of spaces in CCL names is:

• Spaces appearing before or after a name are not consideredto be part of the name.


CFX-PostAdvanced


MasterIndex

Help OnHelp

• Single spaces appearing inside a name are significant.• Multiple spaces and tabs appearing inside a name are treated

as a single space.

Indentation

Nothing in the file is sensitive to indentation. The indentation will beused, however, when displaying contents of the file for easier reading.

End of line comment character

The “#” character is used for this. Any text to the right of this characterwill be treated as comments. Any characters may be used withincomments.

Continuation character

If a line ends with the character “\” the following line will be linked to theexisting line. There is no restriction on the number of continuation lines.

Named Objects

A named object consists of an object type at the start of a line, followedby a “:” followed by an object name. Subsequent lines may defineparameters and child objects associated with this object. The objectdefinition is terminated by the string “END” on a line by itself.

Object names must be unique within the given scope, and the namemust not contain an underscore.

Singleton Objects

A singleton object consists of an object type at the start of a line,followed by a “:”. Subsequent lines may define parameters and childobjects associated with this object. The object definition is terminatedby the string “END” on a line by itself.

The difference between a singleton object and a named object is that(after the data has been processed), a singleton can appear just onceas the child of a parent object, whereas there may be several instancesof a named object of the same type defined with different names.


CFX-PostAdvanced


MasterIndex

Help OnHelp

Parameters

A parameter consists of a parameter name at the start of a line followedby an “=” character followed by a parameter value. A Parameter maybelong to many different object types. For example U Velocity =1.0 [m/s] may belong to an initial value object and U Velocity =2.0 [m/s] may belong to a boundary condition object. Both refer tothe same definition of U velocity in the rules file.

Lists

Lists are used within the context of parameter values and are commaseparated.

Parameter values

All parameter values are initially handled as data of type String, andshould first of all conform to the following definition of allowed Stringvalues:

String

• Any characters can be used in a parameter value.

• String values or other parameter type values are normally unquoted.If any quotes are present, they are considered part of the value.Leading and trailing spaces are ignored. Internal spaces inparameter values are preserved as given, although a givenapplication is free to subsequently assume a space condensationrule when using the data.

• The characters '$' and '#' have a special meaning. A stringbeginning with '$' is evaluated as a Power Syntax variable, even if itoccurs within a simple syntax statement. This is useful forperforming more complex Power Syntax variable manipulation, andthen using the result as part of a parameter or object definition. Theappearance of '#' anywhere in the CCL file denotes the start of acomment.

• The characters such as ’[’ ’]’ ’{’ ’}’ are special only if used inconjunction with ’$’. Following a ’$’, such characters will terminatethe preceding Perl variable name.


CFX-PostAdvanced


MasterIndex

Help OnHelp

• Other characters that might be special elsewhere in power syntaxare escaped automatically when they appear in parameter values.For example, ’@’ ’%’ and ’&’ are escaped automatically.

• Parameter values can contain commas, but if the string isprocessed as a List or part of a List then the commas may beinterpreted as separators (see below under List data types).

Some examples of valid parameter values using special characters inpower syntax are:

Estimated cost = \$500Title = Run\#1Sys Command = "echo ’Starting up Stress solver’ ; fred.exe &"Pressure = $myArray[4]Option = $myHash{"foo"}Fuel = C${numberCatoms}H${numberHatoms}

Parameter values for data types other than String, will additionallyconform to one of the following definitions.

String List

A list of string items separated by commas. Items in a String List shouldNOT contain a comma unless contained between parentheses. Oneexception can be made if the String List to be is interpreted as a RealList (see below). Otherwise each item in the String List follows thesame rules as String data.

Integer

Sequence of digits containing no spaces or commas. If a real isspecified when an integer is needed the real is rounded to the nearestinteger.

Integer List

List of integers, comma separated.

Example: names = one, two, three, four


CFX-PostAdvanced


MasterIndex

Help OnHelp

Real

A single precision real number which may be specified in integer,floating point or scientific format, followed optionally by a dimension.Units use the same syntax as CEL.

Expressions are allowed to include commas inside function callargument lists. Example usage:

a = 12.24a = 1.224E01a = 12.24 [m s^-1]

A real may also be specified as an expression such asa = myvel^2 + ba = max(b,2.0)

Real List

List of reals, comma separated. Note that all items in the list must havethe same dimensions. Those items which are expressions, are allowedto include commas inside function call argument lists, and the enclosedcommas will be ignored when the list is parsed into individual items.Example usage:

a = 1.0 [m/s], 2.0 [m/s], 3.0 [m/s], 2.0*myvel, 4.0 [cm/s]

The list syntax 5*2.0 used in CFX-Build to represent 5 entries of thevalue 2.0 is not supported within CCL and hence within CFX-Post. InCFX-Build the data is expanded prior to being written to the CCL file.

Logical

Several forms are acceptable: YES or TRUE or 1 or ON are allequivalent; NO or FALSE or 0 or OFF are all equivalent; initial lettervariants Y, T, N, F are accepted (O is not accepted (for On/Off); all casevariants are accepted. The preferred form, recommended for GUIoutput files and for user documentation is, Yes/No. Logical strings arealso case insensitive (YeS, nO)

Logical List

List of Logicals, comma separated.


CFX-PostAdvanced


MasterIndex

Help OnHelp

Escape character

The “\” character to be used as an escape character, for example toallow ’$’ or ’#’ to be used in strings.


CFX-PostAdvanced


MasterIndex

Help OnHelp

Object Creation and Deletion

You can create objects in CFX-Post by entering the CCL definition ofthe object into the Command Editor window, or by reading the objectdefinition from a Session or State file. The object will be created andany associated graphics shown in the viewer. For a list of valid CCLobjects see CCL Details (p. 229 in CFX-Post) .

You can modify an existing object by entering the object definition withthe modified parameter settings into the Command Editor window.Only those parameters which are to be changed need to be entered.All other parameters will remain unchanged.

There may be a significant degree of interaction between objects inCFX-Post. For example, a vector plot may depend on the location of anunderlying plane, or an isosurface may depend on the definition of aCEL expression. If changes to one object affect other objects, the otherobjects will be updated automatically.

To delete an object, type >delete <ObjectName> . If you delete anobject that is used by other objects, warnings will result, but the objectwill still be deleted.

Page 172 Object Creation and Deletion CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

CFX Expression Language (CEL)

The CFX Expression Language (CEL) is integrated into CFX-Post. Youcan use an expression defined with CEL in place of any number inCFX-Post. Within the post-processor you can:

• Create new expressions.

• Set any numeric parameter in a CFX-Post object based on anexpression (and the object will update if the expression resultchanges).

• Create user-defined variables from expressions.

• Directly use the post-processor quantitative functions in anexpression.

• Specify units as part of an expression.

You cannot (yet):

• Automatically read CEL expressions from pre-processing set-up inthe results file.

All expressions in the post-processor are defined in theEXPRESSIONS singleton object. Each expression is a simplename = expression statement within that object. New expressionsare added by defining new parameters within the expressions object(the EXPRESSIONS object is special, in that it does not have a pre-defined list of valid parameters).

Important: Since Power Syntax uses Perl mathematical operators,you should exercise caution when combining CEL with Power Syntaxexpressions. For example, in CEL, is represented as 2^2 , but inPerl, would be written 2**2 . If you are unsure about the validity of anoperator in Perl, please consult a Perl reference guide.

22

Page 173 CFX Expression Language (CEL) CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

CEL Functions, Constants and System Variables

Quantitative Functions in CEL

The quantitative functions available from the Function Calculator in theCFX-Post GUI are integrated into CEL and can be used in anyexpression. The general syntax used for these functions in CEL is:

[<Fluid>.]<function>[_<Axis>[_<Coord Frame>]]([<Expression>])@<Location>

where terms in [ ] can be optional depending on the function used andterms in < > should be replaced with the required entry. Someexamples are given below.

area()@inletarea_x()@inletareaAve(Pressure - 10000 [Pa])@outletWater at RTP.force_z()@Default

• [<Fluid>.] is always an optional argument which will default to allfluids in the domain if not specified. For multiphase results it can beset to any single fluid in the domain by entering the fluid namefollowed by a period before the function definition. See the tablebelow for a list of functions that accept this option.

• <function> specifies the quantitative function to evaluate. See thetable below for a list of functions.

• [_<Axis>_[<Coord Frame>]] can be an optional or a requiredargument depending on the function evaluated.[_<Axis>_[<Coord Frame>]] can be replaced with _x, _y or _z(lower case only) to specify the default X, Y and Z axis and shouldfollow the function name. You can use an axis from a differentcoordinate frame by following the axis specification with the name ofthe Coordinate Frame, e.g. _x_CoordFrame1 .

• ([<Expression>]) is a required argument for some functions andshould be left blank as in the above area example (i.e. ())for otherfunction (see the table below for a list). Any valid expression orvariable can be used. You can also use a variable as part of anexpression as shown in the above areaAve example.

• @<Location> is required for all quantitative functions.


CFX-PostAdvanced


MasterIndex

Help OnHelp

Consistent units must be maintained when adding, subtracting orcomparing values.

The following table contains the quantitative function available for usewith CEL. The operation performed by the function and the argumentsaccepted are also shown. A detailed description of the calculationperformed by each function is not provided here, see FunctionSelection (p. 128) for this information.

Function Name Operation RequiredArguments

OptionalArguments

area (p. 176) Area projected to axis (noaxis specification returnstotal area)

@<Location> _<Axis>

areaAve (p. 176) Area-weighted average <Expression>@<Location>

_<Axis>

areaInt (p. 177) Area-weighted integral <Expression><Location>

_<Axis>

ave (p. 177) Arithmetic average <Expression>@<Location>

count (p. 177) Number of calculation points @<Location>

force (p. 177) Force on a surface in thespecified direction

_<Axis>@<Location>

<Fluid>.

forceNorm (p. 178) Length normalised force ona curve in the specifieddirection

_<Axis>@<Location>

<Fluid>.

length (p. 178) Length of a curve @<Location>

lengthAve (p. 178) Length-weighted average <Expression>@<Location>

lengthInt (p. 179) Length-weighted integration <Expression>@<Location>

massFlow (p. 179) Total mass flow @<Location> <Fluid>.

massFlowAve (p. 179) Mass-weighted average <Expression>@<Location>

<Fluid>.

massFlowInt (p. 179) Mass-weighted integral <Expression>@<Location>

<Fluid>.

maxVal (p. 179) Maximum Value <Expression>@<Location>


CFX-PostAdvanced


MasterIndex

Help OnHelp

areaarea[_<Axis>]()@<Location>

An error is raised if the location specified is not a 2-D Object. If an axisis not specified the total area of the location is calculated. See area(p. 129) for a function description.

areaAveareaAve[_<Axis>](<Expression>)@<Location>

An error is raised if the location specified is not a 2-D Object. SeeareaAve (p. 130) for a function description.

minVal (p. 179) Minimum Value <Expression>@<Location>

probe (p. 180) Value at a point <Expression>@<Location>

sum (p. 180) Sum over the calculationpoints

<Expression>@<Location>

torque (p. 180) Torque on a surface aboutthe specified axis

_<Axis>@<Location>

<Fluid>.

volume (p. 180) Volume of a 3-D location @<Location>

volumeAve (p. 180) Volume-weighted average <Expression>@<Location>

volumeInt (p. 180) Volume-weighted integral <Expression>@<Location>

Example: area()@Isosurface1 calculates the total area of thelocation Isosurface1 .

Example: area_y()@Isosurface1 calculates the projected areaof Isosurface1 onto a plane normal to the Y-axis.

Example: (Pressure - 1[bar])/(0.5*Density*(areaAve(Velocity)@inlet)^2)calculates the Pressure coefficient Cp. You can create an expressionusing this, and then create a User Variable using the expression. TheUser Variable can then be plotted on objects like any other variable.

Function Name Operation RequiredArguments

OptionalArguments


CFX-PostAdvanced


MasterIndex

Help OnHelp

areaIntareaInt[_<Axis>](<Expression>)@<Location>

An error is raised if the location specified is not a 2-D Object. Axis isoptional and if not specified the integration is performed over the totalface area. If axis is specified, then the integration is performed over theprojected face area. See areaInt (p. 130) for a function description.

aveave(<Expression>)@<Location>

The ave function can be used on Point, 1-D, 2-D and 3-D locations.See ave (p. 131) for a function description.

countcount()@<Location>

The count function is valid for point, 1-D, 2-D and 3-D locations. Seecount (p. 132) for a function description.

force[<Fluid>.]force_<Axis>()@<Location>

Example: areaInt_y_Frame2(Pressure)@boundary1calculates the pressure force acting in the y-direction of thecoordinate frame Frame2 on the locator boundary1 . This differsfrom a calculation using the force function which calculates the totalforce on a wall boundary (i.e. viscous forces on the boundary areincluded).

Example: ave(Yplus)@Default calculates the mean Yplusvalues from each node on the default walls.

Example: count()@Polyline1 returns the number of points onthe specified Polyline locator.


CFX-PostAdvanced


MasterIndex

Help OnHelp

Force calculations on boundaries require additional momentum flowdata. This can be include in the Results file by adding the ExpertControl Parameter output eq flows and setting its value to T. Seeforce (p. 132) for a function description.

forceNorm[<Fluid>.]forceNorm_<Axis>()@<Location>

Returns the per unit width force on the specified line in the direction ofthe specified axis. An error will be raised if the location specified is notone-dimensional. See forceNorm (p. 133) for a function description.

lengthlength()@<Location>

A 1-D location should be specified (specifying a 2-D location will notproduce an error, the sum of the edge lengths from the elements in thelocator will be returned). Note that when using this function in PowerSyntax the leading character should be capitalised to avoid confusionwith the Perl internal command “length”. See length (p. 133 in CFX-Post) for a function description.

lengthAvelengthAve(<Expression>)@<Location>

A 1-D or 2-D location must be specified. See lengthAve (p. 134) fora function description.

Example: Water at RTP.force_x()@wall1 returns the totalforce in the x-direction acting on wall1 due to the fluid Water at RTP.

Example: forceNorm_y()@Polyline1 calculates the per unitwidth force in the y-direction on the selected Polyline.

Example: length()@Polyline1 returns the length of thePolyline.

Example: lengthAve(T)@Polyline1 calculates the averageTemperature on Polyline1 weighted by the distance betweeneach point (T is the System Variable for Temperature).


CFX-PostAdvanced


MasterIndex

Help OnHelp

lengthIntlengthInt(<Expression>)@<Location>

A 1-D location must be specified. See lengthInt (p. 134) for afunction description.

massFlow[<Fluid>.]massFlow()@<Location>

Computes the mass flow through the specified 2-D location. SeemassFlow (p. 134) for a function description.

massFlowAve[<Fluid>.]massFlowAve(<Expression>)@<Location>

An error is raised if the location specified is not 2-D. SeemassFlowAve (p. 134) for a function description.

massFlowInt[<Fluid>.]massFlowInt(<Expression>)@<Location>

An error is raised if the location specified is not 2-D. SeemassFlowInt (p. 135) for a function description.

maxValmaxVal(<Expression>)@<Location>

Point, and one, two and three-dimensional locators can be specified.See maxVal (p. 135) for a function description.

minValminVal(<Expression>)@<Location>

Point, and one, two and three-dimensional locators can be specified.See minVal (p. 135) for a function description.

Example: Air at STP.massFlow()@DegassingOutletcalculates the mass flow of Air at STP through the selected location.

Example: massFlowAve(Density)@Plane1 calculates theaverage Density on Plane1 weighted by the mass flow at each pointon the location.

9 CFX Expression Language (CEL) CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

probeprobe(<Expression>)@<Location>

Valid only for Point locators, this will return the value of a variable at agiven location. See probe (p. 135) for a function description.

sumsum(<Expression>)@<Location>

One, two and three-dimensional locators can be specified. See sum(p. 136) for a function description.

torque[<Fluid>.]torque_<Axis>()@<Location>

An error is raised if the location specified is not 2-D.See torque(p. 136) for a function description.

volumevolume()@<Location>

An error is raised if the location specified is not a 3-D Object. Seevolume (p. 136) for a function description.

volumeAvevolumeAve(<Expression>)@<Location>

An error is raised if the location specified is not a 3-D Object. Anyvariable or valid expression (see CEL Functions, Constants andSystem Variables (p. 173 in CFX-Post) ) can be used as the<Expression> argument. See volumeAve (p. 137) for a functiondescription.

volumeIntvolumeInt(<Expression>)@<Location>

A 3-D Object must be selected as the location. See volumeInt(p. 137) for a function description.

Example: volumeInt(Density)@StaticMixer calculates thetotal fluid mass in the domain StaticMixer.

0 CFX Expression Language (CEL) CFX-5.5.1

CFX-PostAdvanced


MasterIndex

Help OnHelp

CEL Standard Functions

The following is a list of standard functions that are available inCFX-Post. In the table below:

Note: [ ] denotes a dimensionless quantity. [a] denotes any dimensions of firstoperand.

CEL Constants

The following predefined constants can be used within CELexpressions.

Result Function Operands

[ ] sin ([radian])

[ ] cos ([radian])

[ ] tan ([radian])

[radian] asin ([ ])

[radian] acos ([ ])

[radian] atan ([ ])

[radian] atan2 ([ ],[ ]))

[ ] exp ([ ])

[ ] loge ([ ])

[ ] log10 ([ ])

[a] abs ([a])

[a^0.5] sqrt ([a])

[ ] step ([ ])

[a] min ([a],[a])

[a] max ([a],[a])

Constant Units Description

e <none> Constant : 2.7182817

g m^2 s^-2 Accn. due to gravity : 9.806

pi <none> Constant : 3.1415927


CFX-PostAdvanced


MasterIndex

Help OnHelp

CEL System Variables

The following System Variables are available for use with CEL whendefining expressions:

R m^2 s^-2 K^-1 Universal Gas Constant : 8314.5

Name Meaning

x Direction 1 in Reference Coordinate Frame

y Direction 2 in Reference Coordinate Frame

z Direction 3 in Reference Coordinate Frame

rRadial spatial location,

theta Angle, arctan(y/x)

t Time

u Velocity in the x coordinate direction

v Velocity in the y coordinate direction

w Velocity in the z coordinate direction

p (absolute) Pressure

vf Volume Fraction

ke Turbulent kinetic energy

ed Turbulent eddy dissipation

eddy viscosity Eddy Viscosity

T Temperature

sstrnr Shear strain rate

density Density

viscosity Dynamic Viscosity

Cp Specific Heat Capacity at Constant Pressure

cond Thermal Conductivity

enthalpy Specific Enthalpy

Constant Units Description

r x2

y2

+=


CFX-PostAdvanced


MasterIndex

Help OnHelp

The r, theta t and subdomain values in the above table can only beused if the variables associated with them are output from the solver. rand theta are not calculated by CFX-Post from x, y, z but expressionsto do so can be defined. subdomain is not usually defined inCFX-Post.

Where appropriate, fluid or component names may be prefixed tothese variables i.e. Water at STP.v .

beta Thermal Expansivity

speedofsound Local speed of sound in fluid

subdomain Subdomain variable(1.0 in Subdomain, 0.0 elsewhere)

mean diameter Mean Diameter

deneff Effective Density

AV name Additional Variable name

Name Meaning


CFX-PostAdvanced


MasterIndex

Help OnHelp


cfx command language

Documents