NekVolumeAverage

Compute a volume average of a specified field over the NekRS mesh

Description

This postprocessor computes a volume average of a given field over the NekRS mesh,

where is the volume of the NekRS mesh. To be clear, this postprocessor 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 (-component of velocity)

  • velocity_y (-component of velocity)

  • velocity_z (-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 postprocessors).

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.

Example Input Syntax

As an example, the following code snippet will evaluate the volume averages of temperature, pressure, velocity magnitude, and velocity components over NekRS's mesh.

[Postprocessors]
  [temp_average]
    type = NekVolumeAverage
    field = temperature
  []
  [pressure_average]
    type = NekVolumeAverage
    field = pressure
  []
  [velocity_average]
    type = NekVolumeAverage
    field = velocity
  []
  [x_velocity_average]
    type = NekVolumeAverage
    field = velocity_x
  []
  [y_velocity_average]
    type = NekVolumeAverage
    field = velocity_y
  []
  [z_velocity_average]
    type = NekVolumeAverage
    field = velocity_z
  []
  [velocity_component]
    type = NekVolumeAverage
    field = velocity_component
    velocity_direction = '0.1 0.2 -0.3'
  []
[]
(test/tests/postprocessors/nek_volume_average/nek.i)

Input Parameters

  • fieldField to integrate

    C++ Type:MooseEnum

    Options:velocity_component, velocity_x, velocity_y, velocity_z, velocity, temperature, pressure, scalar01, scalar02, scalar03, unity

    Controllable:No

    Description:Field to integrate

Required Parameters

  • 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.

  • 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

  • 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