FunctionIC

An initial condition that uses a normal function of x, y, z to produce values (and optionally gradients) for a field variable.

Sets an initial condition via a Function described by parameter "function". It can be restricted to particular blocks and boundaries using the "block" and "boundary" parameters, respectively.

To set a function initial condition that preserves an integral of that function, such as for setting a volumetric quantity (units/m) while satisfying a total volume-integral, see the IntegralPreservingFunctionIC.

Example input syntax

In this example, we set the initial value of variable u using a ParsedFunction. This particular example shows that information about the gradient of the parsed function is kept in initial condition, using further mesh refinement.

[ICs<<<{"href": "../../syntax/ICs/index.html"}>>>]
  [u_ic]
    type = FunctionIC<<<{"description": "An initial condition that uses a normal function of x, y, z to produce values (and optionally gradients) for a field variable.", "href": "FunctionIC.html"}>>>
    variable<<<{"description": "The variable this initial condition is supposed to provide values for."}>>> = 'u'
    function<<<{"description": "The initial condition function."}>>> = parsed_function
  []
[]

[Functions<<<{"href": "../../syntax/Functions/index.html"}>>>]
  [parsed_function]
    type = ParsedFunction<<<{"description": "Function created by parsing a string", "href": "../functions/MooseParsedFunction.html"}>>>
    expression<<<{"description": "The user defined function."}>>> = 'sin(x)-cos(y/2)'
  []
  [parsed_grad_function]
    type = ParsedGradFunction<<<{"description": "Defines a function and its gradient using input file parameters.", "href": "../functions/MooseParsedGradFunction.html"}>>>
    expression<<<{"description": "User defined function."}>>> = 'sin(x)-cos(y/2)'
    grad_x<<<{"description": "Partial derivative with respect to x."}>>> = 'cos(x)'
    grad_y<<<{"description": "Partial derivative with respect to y."}>>> = 'sin(y/2)/2'
  []
  [parsed_zerograd_function]
    type = ParsedGradFunction<<<{"description": "Defines a function and its gradient using input file parameters.", "href": "../functions/MooseParsedGradFunction.html"}>>>
    expression<<<{"description": "User defined function."}>>> = 'sin(x)-cos(y/2)'
    grad_x<<<{"description": "Partial derivative with respect to x."}>>> = '0'
    grad_y<<<{"description": "Partial derivative with respect to y."}>>> = '0'
  []
[]
(test/tests/ics/function_ic/parsed_function.i)

Input Parameters

  • functionThe initial condition function.

    C++ Type:FunctionName

    Unit:(no unit assumed)

    Controllable:No

    Description:The initial condition function.

  • variableThe variable this initial condition is supposed to provide values for.

    C++ Type:VariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:The variable this initial condition is supposed to provide values for.

Required Parameters

  • blockThe list of blocks (ids or names) that this object will be applied

    C++ Type:std::vector<SubdomainName>

    Controllable:No

    Description:The list of blocks (ids or names) that this object will be applied

  • boundaryThe list of boundaries (ids or names) from the mesh where this object applies

    C++ Type:std::vector<BoundaryName>

    Controllable:No

    Description:The list of boundaries (ids or names) from the mesh where this object applies

  • scaling_factor1Scaling factor to apply on the function

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Scaling factor to apply on the function

  • stateCURRENTThis parameter is used to set old state solutions at the start of simulation. If specifying multiple states at the start of simulation, use one IC object for each state being specified. The states are CURRENT=0 OLD=1 OLDER=2. States older than 2 are not currently supported. When the user only specifies current state, the solution is copied to the old and older states, as expected. This functionality is mainly used for dynamic simulations with explicit time integration schemes, where old solution states are used in the velocity and acceleration approximations.

    Default:CURRENT

    C++ Type:MooseEnum

    Options:CURRENT, OLD, OLDER

    Controllable:No

    Description:This parameter is used to set old state solutions at the start of simulation. If specifying multiple states at the start of simulation, use one IC object for each state being specified. The states are CURRENT=0 OLD=1 OLDER=2. States older than 2 are not currently supported. When the user only specifies current state, the solution is copied to the old and older states, as expected. This functionality is mainly used for dynamic simulations with explicit time integration schemes, where old solution states are used in the velocity and acceleration approximations.

Optional Parameters

  • control_tagsAdds user-defined labels for accessing object parameters via control logic.

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Set the enabled status of the MooseObject.

  • ignore_uo_dependencyFalseWhen set to true, a UserObject retrieved by this IC will not be executed before the this IC

    Default:False

    C++ Type:bool

    Controllable:No

    Description:When set to true, a UserObject retrieved by this IC will not be executed before the this IC

Advanced Parameters

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

Input Files

Child Objects