TimeDerivativeAux

Returns the time derivative of the specified variable/functor as an auxiliary variable.

The "factor" multiplies the output of the time derivative operation. The time derivative of the "factor" is not computed.

warningwarning

The TimeDerivativeAux is restricted to constructs for which the time derivative is computed by MOOSE. Time derivative functions have not been implemented for all functor types.

Example input syntax

In this example, the TimeDerivativeAux is used to output to auxiliary variables the time derivatives of variables and functions during a time dependent diffusion problem.

[AuxKernels]
  # Time derivative of a nonlinear variable
  [var_derivative]
    type = TimeDerivativeAux
    variable = variable_derivative
    functor = u
    factor = 10
    execute_on = 'TIMESTEP_END'
  []
  # this places the derivative of a FE variable in a FV one
  # let's output a warning
  inactive = 'var_derivative_to_fv'
  [var_derivative_to_fv]
    type = TimeDerivativeAux
    variable = variable_derivative_fv
    functor = u
  []

  # Time derivative of a function: using the functor system
  # Time derivative of a functor material property is not currently supported
  [function_derivative_quadrature_point]
    type = TimeDerivativeAux
    variable = function_derivative_qp
    functor = 'some_function'
    factor = 2
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [function_derivative_element]
    type = TimeDerivativeAux
    variable = function_derivative_elem
    functor = 'some_other_function'
    factor = 2
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[AuxVariables]
  [variable_derivative]
    family = MONOMIAL
    order = CONSTANT
  []
  inactive = 'variable_derivative_fv'
  [variable_derivative_fv]
    family = MONOMIAL
    order = CONSTANT
    fv = true
  []
  [function_derivative_qp]
    family = MONOMIAL
    order = FIRST
  []
  [function_derivative_elem]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[Functions]
  # These functions have implemented time derivatives
  [some_function]
    type = ParsedFunction
    expression = t*(x+y)
  []
  [some_other_function]
    type = PiecewiseLinear
    x = '0 0.05 0.15 0.25'
    y = '1 2 3 4'
  []
[]
(moose/test/tests/auxkernels/time_derivative_aux/test.i)

Input Parameters

  • variableThe name of the variable that this object applies to

    C++ Type:AuxVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the variable that this object applies to

Required Parameters

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

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

    Unit:(no unit assumed)

    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>

    Unit:(no unit assumed)

    Controllable:No

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

  • check_boundary_restrictedTrueWhether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh

  • execute_onLINEAR TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

    Default:LINEAR TIMESTEP_END

    C++ Type:ExecFlagEnum

    Unit:(no unit assumed)

    Options:NONE, INITIAL, LINEAR, NONLINEAR_CONVERGENCE, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, PRE_DISPLACE

    Controllable:No

    Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.

  • factor1Factor to multiply the time derivative by. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    Default:1

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:Factor to multiply the time derivative by. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • functorFunctor to take the time derivative of. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:Functor to take the time derivative of. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • 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

    Unit:(no unit assumed)

    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.

Optional Parameters

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

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

    Unit:(no unit assumed)

    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

    Unit:(no unit assumed)

    Controllable:Yes

    Description:Set the enabled status of the MooseObject.

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Unit:(no unit assumed)

    Controllable:No

    Description:The seed for the master random number generator

  • use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters