FunctionDirichletBC.md|Numbat

# FunctionDirichletBC

Imposes the essential boundary condition $var element = document.getElementById("moose-equation-f4402df5-d180-43fa-abc5-1b4c481d9765");katex.render("u=g(t,\\vec{x})", element, {displayMode:false,throwOnError:false});$ , where $var element = document.getElementById("moose-equation-0c77fd00-1d6d-4ec6-8137-a4383aad9ecc");katex.render("g", element, {displayMode:false,throwOnError:false});$ is a (possibly) time and space-dependent MOOSE Function.

Description

FunctionDirichletBC is a generalization of DirichletBC which imposes a possibly temporally- and spatially-dependent value defined by a MOOSE Function object on a particular set of degrees of freedom (DOFs) defined by the boundary parameter. That is, for a PDE of the form

$(1)var element = document.getElementById("moose-equation-1f1ad5a9-9972-4ba1-b649-d23848ea8078");katex.render("\\begin{aligned} -\\nabla^2 u &= f && \\quad \\in \\Omega \\\\ u &= g(t,\\vec{x}) && \\quad \\in \\partial \\Omega_D \\\\ \\frac{\\partial u}{\\partial n} &= h(t,\\vec{x}) && \\quad \\in \\partial \\Omega_N \\end{aligned}", element, {displayMode:true,throwOnError:false});$

where $var element = document.getElementById("moose-equation-3c878d23-bc55-4601-a8fb-d07bd72f1173");katex.render("\\Omega \\subset \\mathbb{R}^n", element, {displayMode:false,throwOnError:false});$ is the domain, and $var element = document.getElementById("moose-equation-e5932e73-eb7a-4c48-8548-db08a06d1f3e");katex.render("\\partial \\Omega = \\partial \\Omega_D \\cup \\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ is its boundary, a FunctionDirichletBC object can be used to impose the condition (2) if the function is well-defined for $var element = document.getElementById("moose-equation-4c29385c-e364-46ab-87e5-dd5a238ce0cc");katex.render("\\vec{x} \\in \\partial \\Omega_D", element, {displayMode:false,throwOnError:false});$ . In this case, the function parameter corresponds to a MOOSE Function object which represents the mathematical function $var element = document.getElementById("moose-equation-4db66f01-5c63-4d3b-a588-354b07c49523");katex.render("g(t,\\vec{x})", element, {displayMode:false,throwOnError:false});$ , and the user must define one or more sidesets corresponding to the boundary subset $var element = document.getElementById("moose-equation-8568dd6b-9718-4974-a233-0e544bbb7038");katex.render("\\partial \\Omega_D", element, {displayMode:false,throwOnError:false});$ via the boundary parameter.

Example Input Syntax


[BCs]
  active = 'all'

  # Boundary Condition System
  [./all]
    type = FunctionDirichletBC
    variable = u
    boundary = '1 2'
    function = bc_func
  [../]
[]

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

Required Parameters

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_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
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

Tagging Parameters

Description
Example Input Syntax
Input Parameters