- 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
- directionDirection vector to dot with unit normal
C++ Type:libMesh::Point
Controllable:No
Description:Direction vector to dot with unit normal
NekPressureSurfaceForce
Compute pressure force on a surface along a particular direction
Description
This postprocessor computes the integral of the pressure component of the stress tensor over a boundary,
where is the value of the postprocessor, is the boundary of the NekRS mesh, is the unit normal of the boundary, and is a user-specified direction vector. For example, if you set direction = '1 0 0', then you will compute the -component of the pressure drag on the given sideset.
The boundaries over which to compute this postprocessor in the NekRS mesh are specified with the boundary parameter; these boundaries are the sidesets in NekRS's mesh (i.e. the .re2 file). You can specify more than one boundary, with syntax such as boundary = '1 2'. To be clear, this postprocessor is not evaluated on the NekRSMesh mesh mirror, but instead on the mesh actually used for computation in NekRS.
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.
Example Input Syntax
As an example, the postprocessors below compute the pressure surface force on various sidesets in the NekRS mesh.
[Postprocessors]
[pressure_x]
type = NekPressureSurfaceForce
boundary = '1 2 3 4 5 6'
direction = '1 0 0'
mesh = 'fluid'
[]
[pressure_y]
type = NekPressureSurfaceForce
boundary = '1 2 3 4 5 6'
direction = '0 1 0'
mesh = 'fluid'
[]
[pressure_z]
type = NekPressureSurfaceForce
boundary = '1 2 3 4 5 6'
direction = '0 0 1'
mesh = 'fluid'
[]
# These are added to compare by hand
[pressure_x_3]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '3'
[]
[pressure_x_4]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '4'
[]
[pressure_x_comp]
type = DifferencePostprocessor
value1 = pressure_x_3
value2 = pressure_x_4
[]
[pressure_y_1]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '1'
[]
[pressure_y_2]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '2'
[]
[pressure_y_comp]
type = DifferencePostprocessor
value1 = pressure_y_1
value2 = pressure_y_2
[]
[pressure_z_6]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '6'
[]
[pressure_z_5]
type = SideIntegralVariablePostprocessor
variable = P
boundary = '5'
[]
[pressure_z_comp]
type = DifferencePostprocessor
value1 = pressure_z_6
value2 = pressure_z_5
[]
[]
Input 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
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
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.