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

$q^{''}=h(T-T_\infty)$

where $q^{''}$ , $T$ , and $T_\infty$ are each provided by a binned user object which computes these quantities as a function of position. $q^{''}$ and $T$ should each be computed using a NekBinnedSideAverage user object, since these terms represent area integrals over the heated surface, while $T_\infty$ 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]
  [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
  []
[]

Input Parameters

bulk_TUser object containing the averaged bulk temperature
C++ Type:UserObjectName
Unit:(no unit assumed)
Controllable:No
Description:User object containing the averaged bulk temperature
heat_fluxUser object containing the wall-average heat flux
C++ Type:UserObjectName
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
Options:NONE, INITIAL, LINEAR, NONLINEAR_CONVERGENCE, NONLINEAR, 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.
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
Unit:(no unit assumed)
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.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
Controllable:Yes
Description:Set the enabled status of the MooseObject.
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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

(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'
  initial_flux_integral = 1000
  synchronization_interval = constant
  constant_interval = 100
[]

[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 = 'flux_integral'
[]

(tutorials/sfr_7pin/nek_fluxflux.i)

interval = 100

[Mesh]
  type = NekRSMesh
  boundary = '1 2'
[]

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

[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 = '2'
  []
  [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'
  initial_flux_integral = 1000
  synchronization_interval = constant
  constant_interval = 100
[]

[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 = 'flux_integral'
[]

Description
Example Input Syntax
Input Parameters
Input Files