- active__all__ If specified only the blocks named will be visited and made active
Default:__all__
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:If specified only the blocks named will be visited and made active
- familyLAGRANGESpecifies the family of FE shape functions to use for this variable
Default:LAGRANGE
C++ Type:MooseEnum
Unit:(no unit assumed)
Controllable:No
Description:Specifies the family of FE shape functions to use for this variable
- inactiveIf specified blocks matching these identifiers will be skipped.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:If specified blocks matching these identifiers will be skipped.
- initial_conditionSpecifies a constant initial condition for this variable
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Specifies a constant initial condition for this variable
- orderFIRSTSpecifies the order of the FE shape function to use for this variable (additional orders not listed are allowed)
Default:FIRST
C++ Type:MooseEnum
Unit:(no unit assumed)
Controllable:No
Description:Specifies the order of the FE shape function to use for this variable (additional orders not listed are allowed)
- scalingSpecifies a scaling factor to apply to this variable
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Specifies a scaling factor to apply to this variable
Variables System
Description
The Variables block within an input file is utilized to define the unknowns within a system of partial differential equations. These unknowns are often referred to as nonlinear variables within documentation. The nonlinear variables defined within this block are used by Kernel objects to define the equations for a simulation. Also, scalar variables that are constant in space but evolve in time can be described by ordinary differential equations.
Documentation on the major classes of variables are presented in:
MooseVariableBase: for typical finite element nonlinear variables and scalar variables
MooseVariableFV: for finite volume variables
Example
The following input file snippet demonstrates the creation of a single nonlinear variable that is used by two Kernel objects, refer to Example 2 for more details.
[Variables]
[convected]
order = FIRST
family = LAGRANGE
[]
[]
[Kernels]
[diff]
type = Diffusion
variable = convected
[]
[conv]
type = ExampleConvection
variable = convected
velocity = '0.0 0.0 1.0'
[]
[]
Input Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
- isObjectActionTrueIndicates that this is a MooseObjectAction.
Default:True
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Indicates that this is a MooseObjectAction.
Advanced Parameters
Available Objects
- Moose App
- ArrayMooseVariableUsed for grouping standard field variables with the same finite element family and order
- MooseLinearVariableFVRealBase class for Moose variables. This should never be the terminal object type
- MooseVariableRepresents standard field variables, e.g. Lagrange, Hermite, or non-constant Monomials
- MooseVariableBaseBase class for Moose variables. This should never be the terminal object type
- MooseVariableConstMonomialSpecialization for constant monomials that avoids unnecessary loops
- MooseVariableFVRealBase class for Moose variables. This should never be the terminal object type
- MooseVariableScalarMoose wrapper class around scalar variables
- VectorMooseVariableRepresents vector field variables, e.g. Vector Lagrange, Nedelec or Raviart-Thomas
Available Actions
- Moose App
- AddVariableActionAdd a non-linear variable to the simulation.
- CopyNodalVarsActionCopies variable information from a file.