# Submodel End BC

special type of Preset BC that is applied only above and below the ends of a submodel, as determined by postprocessors

## Description

The SubmodelEndBC boundary condition can be used to prescribe different conditions, e.g. displacements, on different subsections of the same model.

## Example Input Syntax


[./ends_x]
type = SubmodelEndBC
variable = disp_x
boundary = 5
function = zero
fuel_stack_top = top_position
fuel_stack_bottom = bottom_position
[../]
(test/tests/submodel_end_bc/submodel_end_bc.i)

## Input Parameters

• functionThe forcing function.

C++ Type:FunctionName

Description:The forcing function.

• variableThe name of the variable that this boundary condition applies to

C++ Type:NonlinearVariableName

Description:The name of the variable that this boundary condition applies to

• boundaryThe list of boundary IDs from the mesh where this boundary condition applies

C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

• fuel_stack_topPostprocessor that defines the axial position of the top of the submodel fuel stack

C++ Type:PostprocessorName

Description:Postprocessor that defines the axial position of the top of the submodel fuel stack

• fuel_stack_bottomPostprocessor that defines the axial position of the bottom of the submodel fuel stack

C++ Type:PostprocessorName

Description:Postprocessor that defines the axial position of the bottom of the submodel fuel stack

### Required Parameters

• axial_axis1Coordinate axis of the axial direction of the fuel stack (0, 1, or 2 for x, y, or z

Default:1

C++ Type:unsigned int

Description:Coordinate axis of the axial direction of the fuel stack (0, 1, or 2 for x, y, or z

• save_inThe name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

C++ Type:std::vector

Description:The name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

• diag_save_inThe name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

C++ Type:std::vector

Description:The name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

### Optional Parameters

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Description:Adds user-defined labels for accessing object parameters via control logic.

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Description:Set the enabled status of the MooseObject.

• seed0The seed for the master random number generator

Default:0

C++ Type:unsigned int

Description:The seed for the master random number generator

• implicitTrueDetermines whether this object is calculated using an implicit or explicit form

Default:True

C++ Type:bool

Description:Determines whether this object is calculated using an implicit or explicit form

• use_displaced_meshTrueWhether 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:True

C++ Type:bool

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

• vector_tagsresidualThe tag for the vectors this Kernel should fill

Default:residual

C++ Type:MultiMooseEnum

Description:The tag for the vectors this Kernel should fill

• extra_vector_tagsThe extra tags for the vectors this Kernel should fill

C++ Type:std::vector

Description:The extra tags for the vectors this Kernel should fill

• matrix_tagssystem timeThe tag for the matrices this Kernel should fill

Default:system time

C++ Type:MultiMooseEnum

Description:The tag for the matrices this Kernel should fill

• extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

C++ Type:std::vector

Description:The extra tags for the matrices this Kernel should fill