MultiApplibMeshToMFEMShapeEvaluationTransfer

Allows transfers of libMesh-based MooseVariables to MFEM variables, via local evaluation of shape functions at target nodal projection points. This class supports transfers between different meshes, from first and second order LAGRANGE and constant MONOMIAL libMesh variable types to scalar MFEM GridFunctions defined on H1 and L2 conforming finite element spaces.

For transfers in the opposite direction, from MFEM-based applications to libMesh-based applications, please see MultiAppMFEMTolibMeshShapeEvaluationTransfer.

General Description

MultiApplibMeshToMFEMShapeEvaluationTransfer executes transfers in three steps:

Extraction of a vector of node positions in the ParFiniteElementSpace of the destination mfem::ParGridFunction, using MFEMNodalProjector.
Interpolation of the source libMesh-based MooseVariable at this set of node locations. Required gather/scatter operations are performed similarly to those in MultiAppGeneralFieldTransfer, with interpolation analogous to MultiAppGeneralFieldShapeEvaluationTransfer.
Projection of the evaluated source variable values onto the destination variable nodes, to set the destination variable degrees of freedom, using MFEMNodalProjector.

Features Supported

All libMesh to MFEM transfers executed from this class should be able to support:

transfers from lowest order scalar LAGRANGE and MONOMIAL variables
transfers from second order scalar LAGRANGE variables
transfers between variables belonging to dissimilar meshes
arbitrary number of parallel processes for both the source and target application
transfers between parent and child applications
transfers between sibling applications (child to child)
transfers from multiple variables to multiple variables
transfers between displaced meshes

Input Parameters

source_variablesVariable(s) to transfer from.
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Variable(s) to transfer from.
variablesVariable(s) to store transferred values in.
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Variable(s) to store transferred values in.

Required Parameters

check_multiapp_execute_onTrueWhen false the check between the multiapp and transfer execute on flags is not performed.
Default:True
C++ Type:bool
Controllable:No
Description:When false the check between the multiapp and transfer execute on flags is not performed.
displaced_source_meshFalseWhether or not to use the displaced mesh for the source mesh.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to use the displaced mesh for the source mesh.
displaced_target_meshFalseWhether or not to use the displaced mesh for the target mesh.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to use the displaced mesh for the target mesh.
execute_onSAME_AS_MULTIAPPThe 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:SAME_AS_MULTIAPP
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, SAME_AS_MULTIAPP, POST_ADAPTIVITY
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.
from_multi_appThe name of the MultiApp to receive data from
C++ Type:MultiAppName
Controllable:No
Description:The name of the MultiApp to receive data from
to_multi_appThe name of the MultiApp to transfer the data to
C++ Type:MultiAppName
Controllable:No
Description:The name of the MultiApp to transfer the data to

Optional Parameters

_called_legacy_paramsTrue
Default:True
C++ Type:bool
Controllable:No
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:Yes
Description:Set the enabled status of the MooseObject.
skip_coordinate_collapsingTrueWhether to skip coordinate collapsing (translation and rotation are still performed, only XYZ, RZ etc collapsing is skipped) when performing mapping and inverse mapping coordinate transformation operations. This parameter should only be set by users who really know what they're doing.
Default:True
C++ Type:bool
Controllable:No
Description:Whether to skip coordinate collapsing (translation and rotation are still performed, only XYZ, RZ etc collapsing is skipped) when performing mapping and inverse mapping coordinate transformation operations. This parameter should only be set by users who really know what they're doing.
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
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

Input Files

(test/tests/mfem/transfers/h1_mfem_parent_libmesh_sub/mfem_parent_scalar.i)
(test/tests/mfem/transfers/displaced/mfem_parent.i)
(test/tests/mfem/transfers/sibling_transfers/main_between_multiapp.i)
(test/tests/mfem/transfers/l2_mfem_parent_libmesh_sub/mfem_parent_scalar.i)

(test/tests/mfem/transfers/h1_mfem_parent_libmesh_sub/mfem_parent_scalar.i)

[Mesh]
  type = MFEMMesh
  file = ../../mesh/square_quad9.e
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [mfem_scalar_var]
    type = MFEMVariable
    fespace = H1FESpace
  []
  [libmesh_scalar_var]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[BCs]
  [sides]
    type = MFEMScalarDirichletBC
    variable = mfem_scalar_var
    coefficient = 1.0
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = mfem_scalar_var
  []
  [source]
    type = MFEMDomainLFKernel
    variable = mfem_scalar_var
    coefficient = 2.0
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
  [jacobi]
    type = MFEMOperatorJacobiSmoother
  []
[]

[Solver]
  type = MFEMHypreGMRES
  preconditioner = boomeramg
  l_tol = 1e-12
  l_max_its = 1000
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[MultiApps]
  [libmesh_app]
    type = FullSolveMultiApp
    input_files = libmesh_sub_scalar.i
    execute_on = 'INITIAL'
  []
[]

[Transfers]
  [transfer_from_libmesh]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    source_variables = libmesh_scalar_var
    variables = libmesh_scalar_var
    from_multi_app = libmesh_app
  []
[]

[Postprocessors]
  [Difference]
    type = MFEML2Error
    variable = mfem_scalar_var
    function = libmesh_scalar_var
    execute_on = TIMESTEP_END
  []
[]

[Outputs]
  file_base = 'mfem_parent_libmesh_sub_scalar_quads'
  csv = true
[]

(test/tests/mfem/transfers/displaced/mfem_parent.i)

[Problem]
  type = MFEMProblem
  solve = false
[]

[Mesh]
  type = MFEMMesh
  file = base_strip.e
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[AuxVariables]
  [indicator_nodal]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[Executioner]
  type = MFEMTransient
  dt = 0.05
  num_steps = 10
[]

[MultiApps]
  [solid_domain]
    type = TransientMultiApp
    input_files = libmesh_child.i
    execute_on = 'initial timestep_begin'
  []
[]

[Transfers]
  [pull_indicator_nodal]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    from_multi_app = solid_domain
    source_variables = solid_indicator
    variables = indicator_nodal
    displaced_source_mesh = true
    execute_on = 'initial timestep_begin'
  []
[]

[Outputs]
  [ParaViewDataCollection]
    type = MFEMParaViewDataCollection
    file_base = OutputData/Displaced
    vtk_format = ASCII
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

(test/tests/mfem/transfers/sibling_transfers/main_between_multiapp.i)

# Base input for testing between-multiapp transfers. It has the following complexities:
# - multiapps may not be run with the same number of ranks
# - both nodal and elemental variables
# - transfers between mixes of nodal and elemental variables
# Tests derived from this input may add or remove complexities through command line arguments

[Problem]
  solve = false
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
[]

[MultiApps]
  [mfem_sub]
    type = TransientMultiApp
    input_files = mfem_sub_between_diffusion.i
  []
  [libmesh_sub]
    type = TransientMultiApp
    input_files = libmesh_sub_between_diffusion.i
  []
[]

[Transfers]
  # Nodal to nodal variables
  [mfem_to_libmesh_nodal_nodal]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    from_multi_app = mfem_sub
    to_multi_app = libmesh_sub
    source_variables = sent_nodal
    variables = received_nodal
  []
  [libmesh_to_mfem_nodal_nodal]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    from_multi_app = libmesh_sub
    to_multi_app = mfem_sub
    source_variables = sent_nodal
    variables = received_nodal
  []

  # Elemental to elemental variables
  [mfem_to_libmesh_elem_elem]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    from_multi_app = mfem_sub
    to_multi_app = libmesh_sub
    source_variables = sent_elem
    variables = received_elem
  []
  [libmesh_to_mfem_elem_elem]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    from_multi_app = libmesh_sub
    to_multi_app = mfem_sub
    source_variables = sent_elem
    variables = received_elem
  []

  # Elemental to nodal variables
  [mfem_to_libmesh_elem_nodal]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    from_multi_app = mfem_sub
    to_multi_app = libmesh_sub
    source_variables = sent_elem
    variables = received_nodal
  []
  [libmesh_to_mfem_elem_nodal]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    from_multi_app = libmesh_sub
    to_multi_app = mfem_sub
    source_variables = sent_elem
    variables = received_nodal
  []

  # Nodal to elemental variables
  [mfem_to_libmesh_nodal_elem]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    from_multi_app = mfem_sub
    to_multi_app = libmesh_sub
    source_variables = sent_nodal
    variables = received_elem
  []
  [libmesh_to_mfem_nodal_elem]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    from_multi_app = libmesh_sub
    to_multi_app = mfem_sub
    source_variables = sent_nodal
    variables = received_elem
  []
[]

[Executioner]
  type = Transient
  num_steps = 1
[]

# Positions used to create multiple subapps for the 1 to N and N to 1 tests
[Positions]
  [mfem_locs]
    type = InputPositions
    positions = '0 0 0
                 0.2 0.5 0'
  []
  [libmesh_locs]
    type = InputPositions
    positions = '0 0 0
                 0.1 0.4 0
                 0.7 0.2 0'
  []
[]

(test/tests/mfem/transfers/l2_mfem_parent_libmesh_sub/mfem_parent_scalar.i)

[Mesh]
  type = MFEMMesh
  file = ../../mesh/square_quad9.e
[]

[Problem]
  type = MFEMProblem
  solve = false
[]

[FESpaces]
  [L2FESpace]
    type = MFEMScalarFESpace
    fec_type = L2
    fec_order = CONSTANT
  []
[]

[Variables]
  [mfem_scalar_var]
    type = MFEMVariable
    fespace = L2FESpace
  []
[]

[AuxVariables]
  [libmesh_scalar_var]
    type = MFEMVariable
    fespace = L2FESpace
  []
[]

[Functions]
  [parsed_function]
    type = ParsedFunction
    expression = 'x*x + y*y'
  []
[]

[ICs]
  [libmesh_scalar_var_ic]
    type = MFEMScalarIC
    variable = 'mfem_scalar_var'
    coefficient = parsed_function
  []
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[MultiApps]
  [libmesh_app]
    type = FullSolveMultiApp
    input_files = libmesh_sub_scalar.i
    execute_on = 'INITIAL'
  []
[]

[Transfers]
  [transfer_from_libmesh]
    type = MultiApplibMeshToMFEMShapeEvaluationTransfer
    source_variables = libmesh_scalar_var
    variables = libmesh_scalar_var
    from_multi_app = libmesh_app
  []
[]

[Postprocessors]
  [Difference]
    type = MFEML2Error
    variable = mfem_scalar_var
    function = libmesh_scalar_var
    execute_on = TIMESTEP_END
  []
[]

[Outputs]
  file_base = 'mfem_parent_libmesh_sub_scalar_quads'
  csv = true
[]

General Description
Features Supported
Input Parameters
Input Files