MultiAppMFEMTolibMeshShapeEvaluationTransfer

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

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

General Description

MultiAppMFEMTolibMeshShapeEvaluationTransfer executes transfers in three steps:

Extraction of a vector of node positions or element centroids of the destination libMesh solution variable (similar to the method used in MultiAppGeneralFieldTransfer).
Interpolation of the source mfem::ParGridFunction at this set of node locations, using mfem::FindPointsGSLIB to perform the required gather/scatter operations to obtain a set of points on the local mesh partition, and perform shape function evaluations at these points.
Projection of the evaluated source variable values onto the destination libMesh variable nodes, to set the destination variable degrees of freedom.

Features Supported

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

transfers to lowest order scalar LAGRANGE and MONOMIAL variables
transfers to 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/displaced/libmesh_parent.i)
(test/tests/mfem/transfers/h1_libmesh_parent_mfem_sub/libmesh_parent_scalar.i)
(test/tests/mfem/transfers/sibling_transfers/main_between_multiapp.i)
(test/tests/mfem/transfers/l2_libmesh_parent_mfem_sub/libmesh_parent_scalar.i)

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

[Mesh]
  type = FileMesh
  file = displaced_indicator_strip.e
  displacements = 'disp_x disp_y'
[]

[Problem]
  kernel_coverage_check = false
  skip_nl_system_check = true
  verbose_multiapps = true
[]

[AuxVariables]
  [background_field]
  []
  [disp_x]
  []
  [disp_y]
  []
[]

[AuxKernels]
  [move]
    type = FunctionAux
    variable = disp_x
    function = 't'
    execute_on = 'TIMESTEP_END'
  []
[]

[MultiApps]
  [background]
    type = TransientMultiApp
    input_files = mfem_child.i
    execute_on = 'initial timestep_begin'
  []
[]

[Transfers]
  [pull_indicator_nodal]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    from_multi_app = background
    source_variables = indicator_field
    variables = background_field
    displaced_target_mesh = true
    execute_on = 'initial timestep_begin'
  []
[]

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

[Outputs]
  [out]
    type = Exodus
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

(test/tests/mfem/transfers/h1_libmesh_parent_mfem_sub/libmesh_parent_scalar.i)

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

[Problem]
  type = FEProblem
[]

[Variables]
  [libmesh_scalar_var]
    family = LAGRANGE
    order = FIRST
  []
[]

[AuxVariables]
  [mfem_scalar_var] # libmesh representation of mfem variable
    family = LAGRANGE
    order = FIRST
  []
[]

[BCs]
  [sides]
    type = DirichletBC
    variable = libmesh_scalar_var
    boundary = 'bottom left right top'
    value = 1.0
  []
[]

[Kernels]
  [diff]
    type = Diffusion
    variable = libmesh_scalar_var
  []
  [source]
    type = BodyForce
    variable = libmesh_scalar_var
    value = 2.0
  []
[]

[Executioner]
  type = Steady
[]

[Outputs]
  file_base = 'libmesh_parent_scalar_mfem_sub_quads'
  exodus = true
  csv = true
[]

[Postprocessors]
  [Difference]
    type = ElementL2Difference
    variable = libmesh_scalar_var
    other_variable = mfem_scalar_var
  []
[]

[MultiApps]
  [mfem_app]
    type = FullSolveMultiApp
    input_files = mfem_sub_scalar.i
    execute_on = 'INITIAL'
  []
[]

[Transfers]
  [transfer_from_mfem]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    source_variables = mfem_scalar_var
    variables = mfem_scalar_var
    from_multi_app = mfem_app
  []
[]

(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_libmesh_parent_mfem_sub/libmesh_parent_scalar.i)

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

[Problem]
  type = FEProblem
  solve = false
[]

[Variables]
  [libmesh_scalar_var]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxVariables]
  [mfem_scalar_var] # libmesh representation of mfem variable
    family = MONOMIAL
    order = CONSTANT
  []
[]

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

[ICs]
  [libmesh_scalar_var_ic]
    type = FunctionIC
    variable = 'libmesh_scalar_var'
    function = parsed_function
  []
[]

[Executioner]
  type = Steady
[]

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

[Postprocessors]
  [Difference]
    type = ElementL2Difference
    variable = libmesh_scalar_var
    other_variable = mfem_scalar_var
  []
[]

[MultiApps]
  [mfem_app]
    type = FullSolveMultiApp
    input_files = mfem_sub_scalar.i
    execute_on = 'INITIAL'
  []
[]

[Transfers]
  [transfer_from_mfem]
    type = MultiAppMFEMTolibMeshShapeEvaluationTransfer
    source_variables = temperature
    variables = mfem_scalar_var
    from_multi_app = mfem_app
  []
[]

General Description
Features Supported
Input Parameters
Input Files