NekBinnedPlaneAverage

Compute the spatially-binned side average of a field over the NekRS mesh

Description

This user objects performs a side average of a specified field over face "bins" defined on the NekRS mesh. For illustration, consider a rectangular face aligned with the $var element = document.getElementById("moose-equation-480b34ff-1817-4b62-9404-c7e975ded835");katex.render("x", element, {displayMode:false,throwOnError:false});$ axis on $var element = document.getElementById("moose-equation-3d4f59a0-b048-480d-b5d8-00860cf02b0d");katex.render("x_0\\leq x\\leq x_1", element, {displayMode:false,throwOnError:false});$ , $var element = document.getElementById("moose-equation-c96066f3-224a-4b5b-984b-c18c0357a85c");katex.render("y=y_0", element, {displayMode:false,throwOnError:false});$ , and $var element = document.getElementById("moose-equation-a4164387-c48b-46cb-95b4-cabb8871dfee");katex.render("z_0\\leq z\\leq z_1", element, {displayMode:false,throwOnError:false});$ . Because this face may not necessarily align with the faces of NekRS's mesh elements, a 2-D face average is approximated as a volume average over a prism with a face-normal thickness of gap_thickness, denoted here as $var element = document.getElementById("moose-equation-a38faaec-1a44-4db3-8884-802dc3f503a2");katex.render("\\Delta", element, {displayMode:false,throwOnError:false});$ :

$var element = document.getElementById("moose-equation-71384c8e-ab9f-4b8a-aabe-8c9c58bd95fd");katex.render("p=\\frac{\\int_{x_0}^{x_1}\\int_{y_0-\\frac{\\Delta}{2}}^{y_0+\\frac{\\Delta}{2}}\\int_{z_0}^{z_1}f\\ dxdydz}{\\int_{x_0}^{x_1}\\int_{y_0-\\frac{\\Delta}{2}}^{y_0+\\frac{\\Delta}{2}}\\int_{z_0}^{z_1}dxdydz}", element, {displayMode:true,throwOnError:false});$

where $var element = document.getElementById("moose-equation-27ecc0ad-f5e3-4fde-bda7-80d507ee3bce");katex.render("p", element, {displayMode:false,throwOnError:false});$ is the value of the user object and $var element = document.getElementById("moose-equation-ce92c409-66f8-46e6-a0ea-d3f1a35c687b");katex.render("f", element, {displayMode:false,throwOnError:false});$ is the specified field. To be clear, this user object is not evaluated on the NekRSMesh mesh mirror, but instead on the mesh actually used for computation in NekRS.

The field is specified with the field parameter, which may be one of:

pressure
temperature
velocity (magnitude of velocity)
velocity_x ( $var element = document.getElementById("moose-equation-395a1222-ad00-48f1-b440-1d79b497a490");katex.render("x", element, {displayMode:false,throwOnError:false});$ -component of velocity)
velocity_y ( $var element = document.getElementById("moose-equation-8c9c79d5-7345-4ce4-9af7-e191e7095242");katex.render("y", element, {displayMode:false,throwOnError:false});$ -component of velocity)
velocity_z ( $var element = document.getElementById("moose-equation-e9576c90-8b50-4bb0-bbdc-931680ed5f07");katex.render("z", element, {displayMode:false,throwOnError:false});$ -component of velocity)
velocity_component (velocity vector projected onto another vector)
scalar01
scalar02
scalar03
unity

Setting field = unity is equivalent to computing 1, since the numerator will be exactly equal to the denominator (unity is of more use for other user objects).

When using field = velocity_component, the manner in which the velocity direction is selected is given by the velocity_component parameter, which may be one of:

normal: normal to the face bins (only valid for the side binning user objects)
user: arbitrary user-specified direction, provided with the velocity_direction parameter

When using a velocity component as the field, this user object computes the dot product of the velocity with the specified direction. To retain the components of the dot product, such as for visualizing vector glyphs of the user object result in Paraview, you can use a NekSpatialBinComponentAux.

If running NekRS in non-dimensional form (and you have indicated the appropriate nondimensional scales by setting nondimensional = true for the [Problem], then the value of this postprocessor is shown in dimensional units. On the otherhand, NekRS scalars (scalar01, scalar02 or scalar03) are never dimensionalized because their dimensions are problem-dependent.

The bins (which can be a combination of side and volume bins) are specified by providing a list of binning user objects with the bin parameter. This user object requires providing one and only one "side" bin, which defines the planes over which to integrate. The available user objects for specifying side spatial bins are:

The side bins can then be combined with any number of "volume" bins to further subdivide the domain. Available user objects for specifying the volume spatial bins are:

If more than one bin is provided, then the bins are taken as the product of each individual bin distribution.

It is recommended to set map_space_by_qp = true for this user object; otherwise, all the GLL points in an element with centroid closer than $var element = document.getElementById("moose-equation-c9c99e6f-bd78-4b45-b90c-2f882d011e01");katex.render("\\Delta/2", element, {displayMode:false,throwOnError:false});$ to the gap plane will contribute to the plane average.

Example Input Syntax

As an example, the input below defines side bins as the gap planes in a hexagonal lattice of pins (named subchannel_binning). These side bins are then combined with a LayeredBin to perform averages over the gap planes in num_layers axial segments.

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 6
  []
  [gap_avg]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = temperature
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
  [gap_area]
    type = NekBinnedPlaneIntegral
    bins = 'subchannel_binning axial_binning'
    field = unity
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

The result of the user object can then be visualized with a SpatialUserObjectAux.

Input Parameters

binsUserobjects providing a spatial bin given a point
C++ Type:std::vector<UserObjectName>
Controllable:No
Description:Userobjects providing a spatial bin given a point
fieldField to postprocess
C++ Type:MooseEnum
Options:velocity_component, velocity_x, velocity_y, velocity_z, velocity, temperature, pressure, scalar01, scalar02, scalar03, unity
Controllable:No
Description:Field to postprocess
gap_thicknessthickness of gap region for which to accept contributions to the side integral over the gap, expressed in the same units as the mesh.
C++ Type:double
Controllable:No
Description:thickness of gap region for which to accept contributions to the side integral over the gap, expressed in the same units as the mesh.

Required Parameters

check_zero_contributionsTrueWhether to throw an error if no GLL points/element centroids in the NekRS mesh map to a spatial bin; this can be used to ensure that the bins are sufficiently big to get at least one contributing point from the NekRS mesh.
Default:True
C++ Type:bool
Controllable:No
Description:Whether to throw an error if no GLL points/element centroids in the NekRS mesh map to a spatial bin; this can be used to ensure that the bins are sufficiently big to get at least one contributing point from the NekRS mesh.
execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.
Default:TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM
Controllable:No
Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.
interval1Frequency (in number of time steps) with which to execute this user object; because Nek uses very small time steps, you need many time steps to reach steady state, and user objects can be expensive and not necessary to evaluate on every single time step. NOTE: you probably want to match this 'interval' in the Output
Default:1
C++ Type:unsigned int
Controllable:No
Description:Frequency (in number of time steps) with which to execute this user object; because Nek uses very small time steps, you need many time steps to reach steady state, and user objects can be expensive and not necessary to evaluate on every single time step. NOTE: you probably want to match this 'interval' in the Output
map_space_by_qpFalseWhether to map the NekRS spatial domain to a bin according to the element centroids (true) or quadrature point locations (false).
Default:False
C++ Type:bool
Controllable:No
Description:Whether to map the NekRS spatial domain to a bin according to the element centroids (true) or quadrature point locations (false).
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
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
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.
velocity_componentDirection with which to evaluate velocity when 'field = velocity_component.' Options: user (specify a direction with 'velocity_direction'), normal (normal to side bins)
C++ Type:MooseEnum
Options:normal, user
Controllable:No
Description:Direction with which to evaluate velocity when 'field = velocity_component.' Options: user (specify a direction with 'velocity_direction'), normal (normal to side bins)
velocity_directionDirection in which to evaluate velocity, for 'field = velocity_component'. For example, velocity_direction = '1 0 0' will get the x-component of velocity.
C++ Type:libMesh::Point
Controllable:No
Description:Direction in which to evaluate velocity, for 'field = velocity_component'. For example, velocity_direction = '1 0 0' will get the x-component of velocity.

Optional Parameters

allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
Default:False
C++ Type:bool
Controllable:No
Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
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.
execution_order_group0Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.
Default:0
C++ Type:int
Controllable:No
Description:Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.
force_postauxFalseForces the UserObject to be executed in POSTAUX
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in POSTAUX
force_preauxFalseForces the UserObject to be executed in PREAUX
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in PREAUX
force_preicFalseForces the UserObject to be executed in PREIC during initial setup
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in PREIC during initial setup
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/userobjects/hexagonal_gap_layered/normals/nek_axial.i)
(test/tests/userobjects/hexagonal_gap_layered/nek.i)
(test/tests/userobjects/hexagonal_gap_layered/normals/nek.i)
(tutorials/subchannel/nek.i)
(test/tests/userobjects/layered_layered/1d.i)
(test/tests/userobjects/hexagonal_gap_layered/nek_axial.i)
(test/tests/userobjects/hexagonal_gap_layered/user_component.i)

(test/tests/userobjects/hexagonal_gap_layered/nek.i)

gap_thickness = ${fparse 0.05 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'temperature'
[]

[AuxVariables]
  [gap_bins]
    family = MONOMIAL
    order = CONSTANT
  []
  [avg_temp]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [gap_bins]
    type = SpatialUserObjectAux
    variable = gap_bins
    user_object = subchannel_binning
  []
  [avg_temp]
    type = SpatialUserObjectAux
    variable = avg_temp
    user_object = gap_avg
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 6
  []
  [gap_avg]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = temperature
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
  [gap_area]
    type = NekBinnedPlaneIntegral
    bins = 'subchannel_binning axial_binning'
    field = unity
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_avg
    to_multi_app = subchannel
    variable = gap_avg
  []
  [uo2_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_area
    to_multi_app = subchannel
    variable = gap_area
  []
  [temp_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    variable = temp
    source_variable = temp
    search_value_conflicts = false
  []
[]

[VectorPostprocessors]
  [avg_temp]
    type = SpatialUserObjectVectorPostprocessor
    userobject = gap_avg
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
  csv = true
[]

(test/tests/userobjects/hexagonal_gap_layered/normals/nek_axial.i)

gap_thickness = ${fparse 0.05 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'velocity'
[]

[AuxVariables]
  # These are just for visualizing the average velocity component with Glyphs in paraview;
  # the result of the 'vol_avg' user object will be represented as a vector "uo_" with 3 components
  [uo_x]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_y]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_z]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [uo_x]
    type = NekSpatialBinComponentAux
    variable = uo_x
    user_object = avg_velocity_component
    component = 0
  []
  [uo_y]
    type = NekSpatialBinComponentAux
    variable = uo_y
    user_object = avg_velocity_component
    component = 1
  []
  [uo_z]
    type = NekSpatialBinComponentAux
    variable = uo_z
    user_object = avg_velocity_component
    component = 2
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredGapBin
    direction = z
    num_layers = 6
  []
  [avg_velocity_component]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = velocity_component
    velocity_component = normal
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel_axial.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uox_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_x
    variable = uo_x
    search_value_conflicts = false
  []
  [uoy_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_y
    variable = uo_y
    search_value_conflicts = false
  []
  [uoz_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_z
    variable = uo_z
    search_value_conflicts = false
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/userobjects/hexagonal_gap_layered/nek.i)

gap_thickness = ${fparse 0.05 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'temperature'
[]

[AuxVariables]
  [gap_bins]
    family = MONOMIAL
    order = CONSTANT
  []
  [avg_temp]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [gap_bins]
    type = SpatialUserObjectAux
    variable = gap_bins
    user_object = subchannel_binning
  []
  [avg_temp]
    type = SpatialUserObjectAux
    variable = avg_temp
    user_object = gap_avg
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 6
  []
  [gap_avg]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = temperature
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
  [gap_area]
    type = NekBinnedPlaneIntegral
    bins = 'subchannel_binning axial_binning'
    field = unity
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_avg
    to_multi_app = subchannel
    variable = gap_avg
  []
  [uo2_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_area
    to_multi_app = subchannel
    variable = gap_area
  []
  [temp_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    variable = temp
    source_variable = temp
    search_value_conflicts = false
  []
[]

[VectorPostprocessors]
  [avg_temp]
    type = SpatialUserObjectVectorPostprocessor
    userobject = gap_avg
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
  csv = true
[]

(test/tests/userobjects/hexagonal_gap_layered/normals/nek.i)

gap_thickness = ${fparse 0.05 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'velocity'
[]

[AuxVariables]
  # These are just for visualizing the average velocity component with Glyphs in paraview;
  # the result of the 'vol_avg' user object will be represented as a vector "uo_" with 3 components
  [uo_x]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_y]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_z]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [uo_x]
    type = NekSpatialBinComponentAux
    variable = uo_x
    user_object = avg_velocity_component
    component = 0
  []
  [uo_y]
    type = NekSpatialBinComponentAux
    variable = uo_y
    user_object = avg_velocity_component
    component = 1
  []
  [uo_z]
    type = NekSpatialBinComponentAux
    variable = uo_z
    user_object = avg_velocity_component
    component = 2
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 6
  []
  [avg_velocity_component]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning'
    field = velocity_component
    velocity_component = normal
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = avg_velocity_component
    to_multi_app = subchannel
    variable = avg_velocity_component
  []
  [uox_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_x
    variable = uo_x
    search_value_conflicts = false
  []
  [uoy_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_y
    variable = uo_y
    search_value_conflicts = false
  []
  [uoz_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_z
    variable = uo_z
    search_value_conflicts = false
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
[]

(tutorials/subchannel/nek.i)

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'temperature velocity'
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [subchannel_gap_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 7
  []
  [average_T]
    type = NekBinnedVolumeAverage
    bins = 'subchannel_binning axial_binning'
    field = temperature
    map_space_by_qp = true
  []
  [average_T_gaps]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_gap_binning axial_binning'
    field = temperature
    map_space_by_qp = true
    gap_thickness = ${fparse 0.05 * 7.646e-3}
  []
  [avg_gap_velocity]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_gap_binning axial_binning'
    field = velocity_component
    velocity_component = normal
    map_space_by_qp = true
    gap_thickness = ${fparse 0.05 * 7.646e-3}
  []
[]

[AuxVariables]
  # These are just for visualizing the average velocity component with Glyphs in paraview;
  # the result of the 'avg_gap_velocity' user object will be represented as a vector "uo_" with 3 components
  [uo_x]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_y]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_z]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [uo_x]
    type = NekSpatialBinComponentAux
    variable = uo_x
    user_object = avg_gap_velocity
    component = 0
  []
  [uo_y]
    type = NekSpatialBinComponentAux
    variable = uo_y
    user_object = avg_gap_velocity
    component = 1
  []
  [uo_z]
    type = NekSpatialBinComponentAux
    variable = uo_z
    user_object = avg_gap_velocity
    component = 2
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel.i'
    execute_on = timestep_end
    sub_cycling = true
  []
  [subchannel_gap]
    type = TransientMultiApp
    input_files = 'subchannel_gap.i'
    execute_on = timestep_end
    sub_cycling = true
  []
[]

[Transfers]
  [uo_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = average_T
    to_multi_app = subchannel
    variable = average_T
  []
  [uo_to_sub2]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = average_T_gaps
    to_multi_app = subchannel_gap
    variable = average_T
  []
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = avg_gap_velocity
    to_multi_app = subchannel_gap
    variable = avg_gap_velocity
  []
  [uox_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel_gap
    source_variable = uo_x
    variable = uo_x
  []
  [uoy_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel_gap
    source_variable = uo_y
    variable = uo_y
  []
[]

[VectorPostprocessors]
  [avg_T]
    type = SpatialUserObjectVectorPostprocessor
    userobject = average_T
  []
  [avg_T_gaps]
    type = SpatialUserObjectVectorPostprocessor
    userobject = average_T_gaps
  []
  [avg_v_gaps]
    type = SpatialUserObjectVectorPostprocessor
    userobject = avg_gap_velocity
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  csv = true
[]

(test/tests/userobjects/layered_layered/1d.i)

[Problem]
  type = NekRSStandaloneProblem
  casename = 'brick'
  output = 'pressure'

  nondimensional = true
  L_ref = 2.0
  U_ref = 1.0
  rho_0 = 834.5
  Cp_0 = 1228.0
  T_ref = 573.0
  dT_ref = 10.0
[]

[Mesh]
  type = NekRSMesh
  volume = true
  scaling = 2.0
[]

[AuxVariables]
  [uo]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [uo]
    type = SpatialUserObjectAux
    variable = uo
    user_object = vol_integral
  []
[]

[UserObjects]
  [x_bins]
    type = LayeredBin
    direction = x
    num_layers = 3
  []
  [x_bins_gaps]
    type = LayeredGapBin
    direction = x
    num_layers = 3
  []
  [vol_integral]
    type = NekBinnedVolumeIntegral
    bins = 'x_bins'
    field = pressure
  []
  [face_avg]
    type = NekBinnedPlaneAverage
    bins = 'x_bins_gaps'
    gap_thickness = 0.1
    map_space_by_qp = true
    field = pressure
  []
[]

[VectorPostprocessors]
  # from_uo gives exactly the same results as manually specifying the points in 'manually_provided'
  [from_uo]
    type = SpatialUserObjectVectorPostprocessor
    userobject = vol_integral
  []
  [manually_provided]
    type = SpatialUserObjectVectorPostprocessor
    userobject = vol_integral
    points = '-0.66666667 0.0 0.0
               0.0        0.0 0.0
               0.66666667 0.0 0.0'
  []
  [from_uo_gap]
    type = SpatialUserObjectVectorPostprocessor
    userobject = face_avg
  []
  [manually_provided_gap]
    type = SpatialUserObjectVectorPostprocessor
    userobject = face_avg
    points = '-1.0     0.0 0.0
              -0.33333 0.0 0.0
               0.33333 0.0 0.0
               1.0     0.0 0.0'
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  csv = true
  exodus = true
  execute_on = 'final'
[]

(test/tests/userobjects/hexagonal_gap_layered/nek_axial.i)

gap_thickness = ${fparse 0.1 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'pressure'
[]

[AuxVariables]
  [gap_bins]
    family = MONOMIAL
    order = CONSTANT
  []
  [avg_p]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [gap_bins]
    type = SpatialUserObjectAux
    variable = gap_bins
    user_object = subchannel_binning
  []
  [avg_p]
    type = SpatialUserObjectAux
    variable = avg_p
    user_object = gap_avg
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredGapBin
    direction = z
    num_layers = 6
  []
  [gap_avg]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = pressure
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
  [gap_area]
    type = NekBinnedPlaneIntegral
    bins = 'subchannel_binning axial_binning'
    field = unity
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel_axial.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_avg
    to_multi_app = subchannel
    variable = gap_avg
  []
  [uo2_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = gap_area
    to_multi_app = subchannel
    variable = gap_area
  []
  [temp_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    variable = P
    source_variable = P
    search_value_conflicts = false
  []
[]

[VectorPostprocessors]
  [avg_p]
    type = SpatialUserObjectVectorPostprocessor
    userobject = gap_avg
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
  csv = true
[]

(test/tests/userobjects/hexagonal_gap_layered/user_component.i)

gap_thickness = ${fparse 0.05 * 7.646e-3}

[Mesh]
  type = NekRSMesh
  volume = true
[]

[Problem]
  type = NekRSStandaloneProblem
  casename = 'sfr_7pin'
  output = 'velocity'
[]

[AuxVariables]
  [velocity_component]
  []

  # These are just for visualizing the average velocity component with Glyphs in paraview;
  # the result of the 'vol_avg' user object will be represented as a vector "uo_" with 3 components
  [uo_x]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_y]
    family = MONOMIAL
    order = CONSTANT
  []
  [uo_z]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [velocity_component] # actual velocity component computed directly from interpolated nekRS velocity fields
    type = ParsedAux
    variable = velocity_component
    expression = '(0.1*vel_x+0.2*vel_y+0.3*vel_z)/sqrt(0.1*0.1+0.2*0.2+0.3*0.3)'
    coupled_variables = 'vel_x vel_y vel_z'
    execute_on = 'timestep_end nonlinear linear'
  []
  [uo_x]
    type = NekSpatialBinComponentAux
    variable = uo_x
    user_object = avg_velocity_component
    component = 0
  []
  [uo_y]
    type = NekSpatialBinComponentAux
    variable = uo_y
    user_object = avg_velocity_component
    component = 1
  []
  [uo_z]
    type = NekSpatialBinComponentAux
    variable = uo_z
    user_object = avg_velocity_component
    component = 2
  []
[]

[UserObjects]
  [subchannel_binning]
    type = HexagonalSubchannelGapBin
    bundle_pitch = 0.02583914354890463
    pin_pitch = 0.0089656996
    pin_diameter = 7.646e-3
    n_rings = 2
  []
  [axial_binning]
    type = LayeredBin
    direction = z
    num_layers = 6
  []
  [avg_velocity_component]
    type = NekBinnedPlaneAverage
    bins = 'subchannel_binning axial_binning'
    field = velocity_component
    velocity_component = user
    velocity_direction = '0.1 0.2 0.3'
    gap_thickness = ${gap_thickness}
    map_space_by_qp = true
  []
[]

[MultiApps]
  [subchannel]
    type = TransientMultiApp
    input_files = 'subchannel_b.i'
    execute_on = timestep_end
  []
[]

[Transfers]
  [uo1_to_sub]
    type = MultiAppGeneralFieldUserObjectTransfer
    source_user_object = avg_velocity_component
    to_multi_app = subchannel
    variable = avg_velocity_component
  []
  [uox_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_x
    variable = uo_x
    search_value_conflicts = false
  []
  [uoy_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_y
    variable = uo_y
    search_value_conflicts = false
  []
  [uoz_to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = uo_z
    variable = uo_z
    search_value_conflicts = false
  []
  [actual_velocity_component]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = subchannel
    source_variable = velocity_component
    variable = velocity_component
    search_value_conflicts = false
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true
[]

Description
Example Input Syntax
Input Parameters
Input Files