- gradient_variableThe variable from which to compute the gradient component
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:The variable from which to compute the gradient component
- 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
VariableGradientComponent
Creates a field consisting of one component of the gradient of a coupled variable.
The result of this operation is stored in an auxiliary variable: variable. The analysis of gradients is useful to examine a solution or the adequacy of a mesh discretization.
commentnote
AuxVariables currently do not contain the Automatic Differentiation information about the derivatives. Using this object in the solve, to compute a material property for example, will lead to an imperfect Jacobian which can impact convergence.
commentnote
VariableGradientComponent may only be applied to elemental variables, and only considers the gradient within an element. For example, the reported gradient of a CONSTANT MONOMIAL is identically zero.
Example Input File Syntax
In this example, u is the (linear) solution of a 2D diffusion equation with no source term. We compute the two gradient components using the AuxKernels below, which each store a gradient component in a separate auxiliary variable. We can then examine the gradient of u, for example to decide to use a finer mesh in a given direction if the corresponding gradient is not well resolved.
[AuxKernels]
[./grad_u_x_aux]
type = VariableGradientComponent
variable = grad_u_x
component = x
gradient_variable = u
[../]
[./grad_u_y_aux]
type = VariableGradientComponent
variable = grad_u_y
component = y
gradient_variable = u
[../]
[]
Input 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
- componentThe gradient component to compute
C++ Type:MooseEnum
Unit:(no unit assumed)
Controllable:No
Description:The gradient component to compute
- 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)
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.
- 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.