PecletNumber

Compute the Peclet number characteristic of the NekRS solution

Description

This postprocessor computes the Peclet number as

(1)

where is the fluid density, is the fluid isobaric specific heat capacity, is the characteristic velocity, is the characteristic length, and is the fluid thermal conductivity. For non-dimensional NekRS cases, this postprocessor can be helpful in confirming that you correctly set all of the various non-dimensional scales in NekRSProblem.

This postprocessor computes Eq. (1) as

(2)

where is a boundary of the NekRS mesh specified with the boundary parameter and is the fluid velocity. If NekRS is run in non-dimensional form, the characteristic length is equal to the L_ref parameter set in NekRSProblem. If NekRS is instead run in dimensional form, the characteristic length must be provided in this postprocessor with the L_ref parameter.

warningwarning

This postprocessor currently assumes that , , and are all constant.

Example Input Syntax

As an example for a dimensional NekRS case, the Pe postprocessor will compute the Peclet number according to the velocity through boundary 1 of the NekRS mesh.

[Postprocessors]
  [Re]
    type = ReynoldsNumber
    L_ref = 0.25
    boundary = '1'
  []
  [Pe]
    type = PecletNumber
    L_ref = 0.25
    boundary = '1'
  []
  [area]
    type = NekSideIntegral
    field = unity
    boundary = '1'
  []
  [mdot]
    type = NekMassFluxWeightedSideIntegral
    field = unity
    boundary = '1'
  []
  [inlet_v]
    type = NekSideAverage
    field = velocity
    boundary = '1'
  []
[]
(test/tests/postprocessors/dimensionless_numbers/dimensional/nek.i)

As an example for a non-dimensional NekRS case, the Pe postprocessor will compute the Peclet number according to the velocity through boundary 1 of the NekRS mesh.

[Postprocessors]
  [Pe]
    type = PecletNumber
    boundary = '1'
  []
  [Re]
    type = ReynoldsNumber
    boundary = '1'
  []
  [area]
    type = NekSideIntegral
    field = unity
    boundary = '1'
  []
  [mdot]
    type = NekMassFluxWeightedSideIntegral
    field = unity
    boundary = '1'
  []
  [inlet_v]
    type = NekSideAverage
    field = velocity
    boundary = '1'
  []
[]
(test/tests/postprocessors/dimensionless_numbers/nondimensional/nek.i)

Input Parameters

  • boundaryBoundary ID(s) for which to compute the postprocessor

    C++ Type:std::vector<int>

    Controllable:No

    Description:Boundary ID(s) for which to compute the postprocessor

Required Parameters

  • L_refReference length scale

    C++ Type:double

    Controllable:No

    Description:Reference length scale

  • 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, TRANSFER

    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.

  • meshallNekRS mesh to compute postprocessor on

    Default:all

    C++ Type:MooseEnum

    Options:fluid, solid, all

    Controllable:No

    Description:NekRS mesh to compute postprocessor on

  • 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.

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

  • outputsVector of output names where you would like to restrict the output of variables(s) associated with this object

    C++ Type:std::vector<OutputName>

    Controllable:No

    Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

  • 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