HeatTransferCoefficientAux

Helper auxiliary kernel to compute a heat transfer coefficient given user objects for heat flux, wall temperature, and bulk temperature.

Description

Helper auxiliary kernel to compute a heat transfer coefficient as

$var element = document.getElementById("moose-equation-46b52dac-d9a6-4c70-bc7f-bb1834820056");katex.render("q^{''}=h(T-T_\\infty)", element, {displayMode:true,throwOnError:false});$

where $var element = document.getElementById("moose-equation-e532b2e8-1752-4698-8fe2-625198daa321");katex.render("q^{''}", element, {displayMode:false,throwOnError:false});$ , $var element = document.getElementById("moose-equation-89e25182-98c7-4e46-af2f-0c966f8d5fc1");katex.render("T", element, {displayMode:false,throwOnError:false});$ , and $var element = document.getElementById("moose-equation-d6e2504f-ca1e-410b-a2db-a617c4e167a9");katex.render("T_\\infty", element, {displayMode:false,throwOnError:false});$ are each provided by a binned user object which computes these quantities as a function of position. $var element = document.getElementById("moose-equation-319133c0-e087-4c2e-b1c5-b738285fd473");katex.render("q^{''}", element, {displayMode:false,throwOnError:false});$ and $var element = document.getElementById("moose-equation-551b49a0-6c87-4cd4-8198-d0b2d3335c81");katex.render("T", element, {displayMode:false,throwOnError:false});$ should each be computed using a NekBinnedSideAverage user object, since these terms represent area integrals over the heated surface, while $var element = document.getElementById("moose-equation-42d2276b-4b00-4a4f-bf5b-d4b648b4ce46");katex.render("T_\\infty", element, {displayMode:false,throwOnError:false});$ should be computed using a NekBinnedVolumeAverage user object, since this term represents a volume integral over the heated fluid volume.

Example Input Syntax

The example below shows how to correctly compute a heat transfer coefficient.

[UserObjects<<<{"href": "../../syntax/UserObjects/index.html"}>>>]
  [axial]
    type = LayeredBin<<<{"description": "Creates a unique spatial bin for layers in a specified direction", "href": "../userobjects/LayeredBin.html"}>>>
    num_layers<<<{"description": "The number of layers between the bounding box of the domain"}>>> = 5
    direction<<<{"description": "The direction of the layers (x, y, or z)"}>>> = z
  []
  [q]
    type = NekBinnedSideAverage<<<{"description": "Compute the spatially-binned average of a field over a sideset of the NekRS mesh", "href": "../userobjects/NekBinnedSideAverage.html"}>>>
    field<<<{"description": "Field to apply this object to"}>>> = usrwrk00
    bins<<<{"description": "Userobjects providing a spatial bin given a point"}>>> = 'axial'
    boundary<<<{"description": "Boundary ID(s) over which to compute the bin values"}>>> = '1'
    interval<<<{"description": "Frequency (in number of time steps) with which to execute this user object; user objects can be expensive and not necessary to evaluate on every single time step. NOTE: you probably want to match with 'time_step_interval' in the Output"}>>> = 100
  []
  [Tw]
    type = NekBinnedSideAverage<<<{"description": "Compute the spatially-binned average of a field over a sideset of the NekRS mesh", "href": "../userobjects/NekBinnedSideAverage.html"}>>>
    field<<<{"description": "Field to apply this object to"}>>> = temperature
    bins<<<{"description": "Userobjects providing a spatial bin given a point"}>>> = 'axial'
    boundary<<<{"description": "Boundary ID(s) over which to compute the bin values"}>>> = '1'
    interval<<<{"description": "Frequency (in number of time steps) with which to execute this user object; user objects can be expensive and not necessary to evaluate on every single time step. NOTE: you probably want to match with 'time_step_interval' in the Output"}>>> = 100
  []
  [Tinf]
    type = NekBinnedVolumeAverage<<<{"description": "Compute the spatially-binned volume average of a field over the NekRS mesh", "href": "../userobjects/NekBinnedVolumeAverage.html"}>>>
    field<<<{"description": "Field to apply this object to"}>>> = temperature
    bins<<<{"description": "Userobjects providing a spatial bin given a point"}>>> = 'axial'
    interval<<<{"description": "Frequency (in number of time steps) with which to execute this user object; user objects can be expensive and not necessary to evaluate on every single time step. NOTE: you probably want to match with 'time_step_interval' in the Output"}>>> = 100
  []
[]

Input Parameters

bulk_TUser object containing the averaged bulk temperature
C++ Type:UserObjectName
Controllable:No
Description:User object containing the averaged bulk temperature
heat_fluxUser object containing the wall-average heat flux
C++ Type:UserObjectName
Controllable:No
Description:User object containing the wall-average heat flux
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
wall_TUser object containing the wall-averaged temperature
C++ Type:UserObjectName
Controllable:No
Description:User object containing the wall-averaged temperature

Required Parameters

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
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>
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
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
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
Options:NONE, INITIAL, LINEAR, LINEAR_CONVERGENCE, NONLINEAR, NONLINEAR_CONVERGENCE, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, PRE_DISPLACE
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.

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:Yes
Description:Set the enabled status of the MooseObject.
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
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
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

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
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.

Material Property Retrieval Parameters

Input Files

(tutorials/sfr_7pin/nek_fluxflux.i)
(test/tests/auxkernels/heat_transfer_coefficient/nek.i)

(test/tests/auxkernels/heat_transfer_coefficient/nek.i)

[Problem]
  type = NekRSProblem
  casename = 'sfr_pin'
  synchronization_interval = constant
  constant_interval = 100

  [FieldTransfers]
    [avg_flux]
      type = NekBoundaryFlux
      direction = to_nek
      usrwrk_slot = 0
      initial_flux_integral = 1000
    []
  []
[]

[Mesh]
  type = NekRSMesh
  boundary = '1'
[]

[UserObjects]
  [axial]
    type = LayeredBin
    num_layers = 5
    direction = z
  []
  [q]
    type = NekBinnedSideAverage
    field = usrwrk00
    bins = 'axial'
    boundary = '1'
    interval = 100
  []
  [Tw]
    type = NekBinnedSideAverage
    field = temperature
    bins = 'axial'
    boundary = '1'
    interval = 100
  []
  [Tinf]
    type = NekBinnedVolumeAverage
    field = temperature
    bins = 'axial'
    interval = 100
  []
[]

[AuxVariables]
  [h]
  []
[]

[AuxKernels]
  [h]
    type = HeatTransferCoefficientAux
    variable = h
    heat_flux = q
    wall_T = Tw
    bulk_T = Tinf
  []
[]

[ICs]
  [avg_flux]
    type = ConstantIC
    variable = avg_flux
    value = 10.0
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Postprocessors]
  # for the boundary mesh mirror, this is a boundary average integral
  [avg_h_uo]
    type = ElementAverageValue
    variable = h
  []

  [avg_wall_flux]
    type = NekSideAverage
    boundary = '1'
    field = usrwrk00
  []
  [avg_wall_T]
    type = NekSideAverage
    boundary = '1'
    field = temperature
  []
  [avg_bulk_T]
    type = NekVolumeAverage
    field = temperature
  []
  [avg_h]
    type = ParsedPostprocessor
    expression = 'avg_wall_flux/(avg_wall_T-avg_bulk_T)'
    pp_names = 'avg_wall_flux avg_wall_T avg_bulk_T'
  []
[]

[Outputs]
  csv = true
  time_step_interval = 100
  hide = 'avg_flux_integral'
[]

(tutorials/sfr_7pin/nek_fluxflux.i)

interval = 100

[Mesh]
  type = NekRSMesh
  boundary = '1 4'
[]

[Problem]
  type = NekRSProblem
  casename = 'sfr_7pin'
  synchronization_interval = parent_app

  [FieldTransfers]
    [heat_flux]
      type = NekBoundaryFlux
      direction = to_nek
      usrwrk_slot = 0
    []
    [temperature]
      type = NekFieldVariable
      direction = from_nek
    []
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Outputs]
  exodus = true

  # this will only display the NekRS output every N time steps; postprocessors
  # are still computed on every step, just not output to the console
  time_step_interval = ${interval}
[]

[UserObjects]
  [axial_bin]
    type = LayeredBin
    direction = z
    num_layers = 20
  []
  [volume_bin]
    type = HexagonalSubchannelBin
    bundle_pitch = ${fparse 0.02625*1.1}
    pin_pitch = 0.00904000030292588
    pin_diameter = 8e-3
    n_rings = 2
  []
  [wall_flux]
    type = NekBinnedSideAverage
    bins = 'axial_bin volume_bin'
    boundary = '1'
    field = usrwrk00
    map_space_by_qp = true
    interval = ${interval}
    check_zero_contributions = false
  []
  [wall_temp]
    type = NekBinnedSideAverage
    bins = 'axial_bin volume_bin'
    boundary = '1'
    field = temperature
    map_space_by_qp = true
    interval = ${interval}
    check_zero_contributions = false
  []
  [bulk_temp]
    type = NekBinnedVolumeAverage
    bins = 'axial_bin volume_bin'
    field = temperature
    map_space_by_qp = true
    interval = ${interval}
    check_zero_contributions = false
  []
[]

[AuxVariables]
  [h]
  []
[]

[AuxKernels]
  [h]
    type = HeatTransferCoefficientAux
    variable = h
    wall_T = wall_temp
    bulk_T = bulk_temp
    heat_flux = wall_flux
  []
[]

[Postprocessors]
  [pin_flux_in_nek]
    type = NekHeatFluxIntegral
    boundary = '1'
  []
  [duct_flux_in_nek]
    type = NekHeatFluxIntegral
    boundary = '4'
  []
  [max_nek_T]
    type = NekVolumeExtremeValue
    field = temperature
    value_type = max
  []
  [min_nek_T]
    type = NekVolumeExtremeValue
    field = temperature
    value_type = min
  []
[]

(test/tests/auxkernels/heat_transfer_coefficient/nek.i)

[Problem]
  type = NekRSProblem
  casename = 'sfr_pin'
  synchronization_interval = constant
  constant_interval = 100

  [FieldTransfers]
    [avg_flux]
      type = NekBoundaryFlux
      direction = to_nek
      usrwrk_slot = 0
      initial_flux_integral = 1000
    []
  []
[]

[Mesh]
  type = NekRSMesh
  boundary = '1'
[]

[UserObjects]
  [axial]
    type = LayeredBin
    num_layers = 5
    direction = z
  []
  [q]
    type = NekBinnedSideAverage
    field = usrwrk00
    bins = 'axial'
    boundary = '1'
    interval = 100
  []
  [Tw]
    type = NekBinnedSideAverage
    field = temperature
    bins = 'axial'
    boundary = '1'
    interval = 100
  []
  [Tinf]
    type = NekBinnedVolumeAverage
    field = temperature
    bins = 'axial'
    interval = 100
  []
[]

[AuxVariables]
  [h]
  []
[]

[AuxKernels]
  [h]
    type = HeatTransferCoefficientAux
    variable = h
    heat_flux = q
    wall_T = Tw
    bulk_T = Tinf
  []
[]

[ICs]
  [avg_flux]
    type = ConstantIC
    variable = avg_flux
    value = 10.0
  []
[]

[Executioner]
  type = Transient

  [TimeStepper]
    type = NekTimeStepper
  []
[]

[Postprocessors]
  # for the boundary mesh mirror, this is a boundary average integral
  [avg_h_uo]
    type = ElementAverageValue
    variable = h
  []

  [avg_wall_flux]
    type = NekSideAverage
    boundary = '1'
    field = usrwrk00
  []
  [avg_wall_T]
    type = NekSideAverage
    boundary = '1'
    field = temperature
  []
  [avg_bulk_T]
    type = NekVolumeAverage
    field = temperature
  []
  [avg_h]
    type = ParsedPostprocessor
    expression = 'avg_wall_flux/(avg_wall_T-avg_bulk_T)'
    pp_names = 'avg_wall_flux avg_wall_T avg_bulk_T'
  []
[]

[Outputs]
  csv = true
  time_step_interval = 100
  hide = 'avg_flux_integral'
[]

Description
Example Input Syntax
Input Parameters
Input Files