NeumannBC

Imposes the integrated boundary condition $var element = document.getElementById("moose-equation-6ab92d5d-8c6e-4ba6-8af5-27627b6cd3b4");katex.render("\\frac{\\partial u}{\\partial n}=h", element, {displayMode:false,throwOnError:false});$ , where $var element = document.getElementById("moose-equation-f1287e4b-27c1-4f77-ab40-3a7908e71aa5");katex.render("h", element, {displayMode:false,throwOnError:false});$ is a constant, controllable value.

Description

NeumannBC is the simplest type of IntegratedBC, and is used for imposing flux boundary conditions on systems of partial differential equations (PDEs). This class is appropriate to use for PDEs of the form $(1)var element = document.getElementById("moose-equation-ebd444f2-5dd4-477b-b933-77f80476f375");katex.render("\\begin{aligned} -\\nabla^2 u &= f && \\quad \\in \\Omega \\\\ u &= g && \\quad \\in \\partial \\Omega_D \\\\ \\frac{\\partial u}{\\partial n} &= h && \\quad \\in \\partial \\Omega_N, \\end{aligned}", element, {displayMode:true,throwOnError:false});$ where $var element = document.getElementById("moose-equation-0615118f-176a-4cb1-ad6d-05b0889c9366");katex.render("\\Omega \\subset \\mathbb{R}^n", element, {displayMode:false,throwOnError:false});$ is the domain, and $var element = document.getElementById("moose-equation-0adfb88e-4f31-42da-b42b-03a0997f62a0");katex.render("\\partial \\Omega = \\partial \\Omega_D \\cup \\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ is its boundary. In this case, a NeumannBC object is used to impose the condition (3) on the subset of the boundary denoted by $var element = document.getElementById("moose-equation-4b85dbc6-9a85-4aa8-bcf9-6cef8def1367");katex.render("\\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ . The value parameter corresponds to the constant $var element = document.getElementById("moose-equation-b50a581e-894d-47ca-9863-44fa9679ebf1");katex.render("h", element, {displayMode:false,throwOnError:false});$ , and the user must define one or more sidesets corresponding to the boundary subset $var element = document.getElementById("moose-equation-d512f3cc-6d57-4590-8f2d-9102509bda25");katex.render("\\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ . The normal derivative notation is $var element = document.getElementById("moose-equation-9ac147fe-70cb-42bf-9707-6fdf665abdb2");katex.render("\\frac{\\partial u}{\\partial n} \\equiv \\nabla u \\cdot \\hat{n}", element, {displayMode:false,throwOnError:false});$ , where $var element = document.getElementById("moose-equation-5504e07d-1b60-40b8-9bec-e5d1a191c5a1");katex.render("\\hat{n}", element, {displayMode:false,throwOnError:false});$ is the outward unit normal to $var element = document.getElementById("moose-equation-6c9479ba-c624-4382-8e26-a7f7fb2b13c1");katex.render("\\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ .

Example Input Syntax

  [./right]
    type = NeumannBC
    variable = u
    boundary = right
    value = 2
  [../]

Input Parameters

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

value0The value of the gradient on the boundary.
Default:0
C++ Type:double
Description:The value of the gradient on the boundary.

Optional Parameters

enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Description:Set the enabled status of the MooseObject.
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.)
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.
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.
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Description:The seed for the master random number generator
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.)
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

Advanced Parameters

vector_tagsnontimeThe tag for the vectors this Kernel should fill
Default:nontime
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_tagssystemThe tag for the matrices this Kernel should fill
Default:system
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