MFEMNDtoRTAux

Overview

Auxkernel for copying the DoFs of a source variable defined on an conforming Nedelec (ND) finite element (FE) space into a target variable defined on an conforming Raviart-Thomas (RT) FE space.

This auxkernel is intended ONLY for two-dimensional MFEM ND to RT FE spaces. In 2D MFEM, the ND to RT bases are related by a 90 degree rotation, so copying the ND coefficients into a compatible RT space can be used to represent the rotated field.

This is useful in 2D magnetostatic postprocessing. After solving for the scalar field , representing the out-of-plane component of the magnetic vector potential, the gradient may be computed in an ND space using MFEMGradAux. The magnetic flux density is then given by a 90-degree rotation of this gradient.

Example Input File Syntax

[AuxKernels<<<{"href": "../../../syntax/AuxKernels/index.html"}>>>]
  [J]
    type = MFEMScalarProjectionAux<<<{"description": "Projects a scalar coefficient onto a scalar MFEM auxvariable", "href": "MFEMScalarProjectionAux.html"}>>>
    variable<<<{"description": "The name of the variable that this object applies to"}>>> = J
    coefficient<<<{"description": "Name of the scalar coefficient to project. A functor is any of the following: a variable, an MFEM material property, a function, a postprocessor or a number."}>>> = J_source
  []
  [gradAz]
    type = MFEMGradAux<<<{"description": "Calculates the gradient of an H1 conforming source variable and stores the result on an H(curl) conforming ND result auxvariable", "href": "MFEMGradAux.html"}>>>
    variable<<<{"description": "The name of the variable that this object applies to"}>>> = gradAz
    source<<<{"description": "Scalar H1 MFEMVariable to take the gradient of."}>>> = Az
  []
  [B_from_gradAz]
    type = MFEMNDtoRTAux<<<{"description": "Copies the DoFs of a 2D Nedelec H(curl) MFEM Variable into a Raviart-Thomas H(div) MFEM Variable. In 2D ONLY this represents a 90 degree rotation because the RT basis is the rotated ND basis.", "href": "MFEMNDtoRTAux.html"}>>>
    variable<<<{"description": "The name of the variable that this object applies to"}>>> = B
    source<<<{"description": "Name of H(curl) conforming ND variable to copy."}>>> = gradAz
    scale_factor<<<{"description": "Optional scale factor. Negative values can be used to flip the sign of the rotation."}>>> = 1.0
  []
[]
(test/tests/mfem/auxkernels/2Dmagnetostatic.i)

Input Parameters

  • sourceName of H(curl) conforming ND variable to copy.

    C++ Type:VariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:Name of H(curl) conforming ND variable to copy.

  • 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

  • execute_onTIMESTEP_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:TIMESTEP_END

    C++ Type:ExecFlagEnum

    Options:XFEM_MARK, FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, LINEAR_CONVERGENCE, NONLINEAR, NONLINEAR_CONVERGENCE, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, MULTIAPP_FIXED_POINT_CONVERGENCE, FINAL, CUSTOM

    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.

  • scale_factor1Optional scale factor. Negative values can be used to flip the sign of the rotation.

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Optional scale factor. Negative values can be used to flip the sign of the rotation.

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.

Advanced Parameters

Input Files