INSADDisplaceBoundaryBC

Boundary condition for displacing a boundary

This boundary condition displaces a boundary in proportion to a coupled velocity. It is a strongly enforced boundary condition on every displacement node with a residual of the form

u(uold+Δtvi)u - (u_{old} + \Delta t \vec{v}_i)

where uu denotes a given displacement vector component, uoldu_{old} is the previous timestep's value of the displacement, Δt\Delta t is the timestep, and vi\vec{v}_i is a component of the coupled velocity vector, where ii denotes the component.

Note that the formula above is appropriate for an ImplicitEuler discretization of time derivatives. Consequently this class will error if the time integrator used is not ImplicitEuler.

Using a Laplacian, e.g. something like Diffusion, for the displacement fields will smooth the interior mesh as the mesh is deformed through this boundary condition. However, it is still possible to run into poor aspect ratio elements, or if you have more tangential displacement at one boundary node than another then you can get inverted elements.

Input Parameters

  • associated_subdomainThe subdomain that the boundary nodeset is associated with. This will be passed to the coupled functor for unambigious evaluation (e.g. at the edge of the node-patch where we might run into the intersection of subdomains

    C++ Type:SubdomainName

    Controllable:No

    Description:The subdomain that the boundary nodeset is associated with. This will be passed to the coupled functor for unambigious evaluation (e.g. at the edge of the node-patch where we might run into the intersection of subdomains

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

    C++ Type:std::vector<BoundaryName>

    Controllable:No

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

  • componentWhat component of velocity/displacement this object is acting on.

    C++ Type:unsigned short

    Controllable:No

    Description:What component of velocity/displacement this object is acting on.

  • variableThe name of the variable that this residual object operates on

    C++ Type:NonlinearVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the variable that this residual object operates on

  • velocityThe velocity at which to displace. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The velocity at which to displace. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number.

Required Parameters

  • 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<AuxVariableName>

    Unit:(no unit assumed)

    Controllable:No

    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.)

  • displacementsThe displacements

    C++ Type:std::vector<VariableName>

    Unit:(no unit assumed)

    Controllable:No

    Description:The displacements

  • matrix_onlyFalseWhether this object is only doing assembly to matrices (no vectors)

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether this object is only doing assembly to matrices (no vectors)

  • 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<AuxVariableName>

    Unit:(no unit assumed)

    Controllable:No

    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.)

Optional Parameters

  • absolute_value_vector_tagsThe tags for the vectors this residual object should fill with the absolute value of the residual contribution

    C++ Type:std::vector<TagName>

    Controllable:No

    Description:The tags for the vectors this residual object should fill with the absolute value of the residual contribution

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

    C++ Type:std::vector<TagName>

    Controllable:No

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

  • extra_vector_tagsThe extra tags for the vectors this Kernel should fill

    C++ Type:std::vector<TagName>

    Controllable:No

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

Contribution To Tagged Field Data Parameters

  • 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.

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

    Default:True

    C++ Type:bool

    Controllable:No

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

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Controllable:No

    Description:The seed for the master random number generator

  • 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

  • matrix_tagssystem timeThe tag for the matrices this Kernel should fill

    Default:system time

    C++ Type:MultiMooseEnum

    Options:nontime, system, time

    Controllable:No

    Description:The tag for the matrices this Kernel should fill

  • vector_tagsresidualThe tag for the vectors this Kernel should fill

    Default:residual

    C++ Type:MultiMooseEnum

    Options:nontime, time, residual

    Controllable:No

    Description:The tag for the vectors this Kernel should fill

Tagging Parameters

Input Files