- diffusivity_functorFunctor specifying the diffusivity. 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:Functor specifying the diffusivity. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number. 
DiffusionFV
Add diffusion physics discretized with cell-centered finite volume
See the DiffusionPhysicsBase documentation for the diffusion equation solved.
Finite Volume Discretization
The volumetric discretization of the time derivative uses the FVTimeKernel kernel. The diffusion term is integrated by parts and represented using a FVDiffusion kernel. The source term is added using:
- a FVBodyForce if the source is a constant, a Postprocessor or a Function 
- a FVCoupledForce if the source is another type of functor 
The Dirichlet boundary conditions are created using:
- a FVDirichletBC if the boundary value is set to a number 
- a FVFunctionDirichletBC if set to a Function 
- a FVFunctorDirichletBC for any other kind of functor for the boundary value 
The Neumann boundary conditions are created using:
- a FVNeumannBC if the flux is set to a number 
- a FVFunctionNeumannBC if set to a Function 
- a FVFunctorNeumannBC for any other kind of functor for the flux value 
We could use a Functor object to cover every need, but the specialized objects are a few percent faster, depending on the case.
Input Parameters
- blockBlocks (subdomains) that this Physics is active on.C++ Type:std::vector<SubdomainName> Controllable:No Description:Blocks (subdomains) that this Physics is active on. 
- compute_diffusive_fluxes_onSurfaces to compute the diffusive flux onC++ Type:std::vector<BoundaryName> Controllable:No Description:Surfaces to compute the diffusive flux on 
- initial_conditionInitial condition for the diffused variableC++ Type:FunctionName Unit:(no unit assumed) Controllable:No Description:Initial condition for the diffused variable 
- source_coef1Coefficient multiplying the sourceDefault:1 C++ Type:double Unit:(no unit assumed) Controllable:No Description:Coefficient multiplying the source 
- source_functorSource term in the diffusion problem. 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:Source term in the diffusion problem. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number. 
- system_namesnl0 Name of the solver system(s) for the variables. If a single name is specified, that system is used for all solver variables.Default:nl0 C++ Type:std::vector<SolverSystemName> Controllable:No Description:Name of the solver system(s) for the variables. If a single name is specified, that system is used for all solver variables. 
- transientsame_as_problemWhether the physics is to be solved as a transientDefault:same_as_problem C++ Type:MooseEnum Controllable:No Description:Whether the physics is to be solved as a transient 
- variable_nameuVariable name for the equationDefault:u C++ Type:VariableName Unit:(no unit assumed) Controllable:No Description:Variable name for the equation 
- verboseFalseFlag to facilitate debugging a PhysicsDefault:False C++ Type:bool Controllable:No Description:Flag to facilitate debugging a Physics 
Optional Parameters
- active__all__ If specified only the blocks named will be visited and made activeDefault:__all__ C++ Type:std::vector<std::string> Controllable:No Description:If specified only the blocks named will be visited and made active 
- 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. 
- ghost_layers2Number of ghosting layers for distributed memory parallel calculationsDefault:2 C++ Type:unsigned short Controllable:No Description:Number of ghosting layers for distributed memory parallel calculations 
- inactiveIf specified blocks matching these identifiers will be skipped.C++ Type:std::vector<std::string> Controllable:No Description:If specified blocks matching these identifiers will be skipped. 
Advanced Parameters
- boundary_fluxesFunctors to compute the diffusive flux on each Neumann boundary'. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number.C++ Type:std::vector<MooseFunctorName> Unit:(no unit assumed) Controllable:No Description:Functors to compute the diffusive flux on each Neumann boundary'. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number. 
- boundary_valuesFunctors to compute the diffusive flux on each Dirichlet boundary'. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number.C++ Type:std::vector<MooseFunctorName> Unit:(no unit assumed) Controllable:No Description:Functors to compute the diffusive flux on each Dirichlet boundary'. A functor is any of the following: a variable, a functor material property, a function, a postprocessor or a number. 
- dirichlet_boundariesBoundaries on which to apply a fixed valueC++ Type:std::vector<BoundaryName> Controllable:No Description:Boundaries on which to apply a fixed value 
- neumann_boundariesBoundaries on which to apply a diffusive fluxC++ Type:std::vector<BoundaryName> Controllable:No Description:Boundaries on which to apply a diffusive flux 
Boundary Conditions Parameters
- dont_create_aux_kernelsFalseWhether to skip the 'add_aux_kernel' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_aux_kernel' task 
- dont_create_aux_variablesFalseWhether to skip the 'add_aux_variable' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_aux_variable' task 
- dont_create_bcsFalseWhether to skip the 'add_bc' task for each boundary condition typeDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_bc' task for each boundary condition type 
- dont_create_correctorsFalseWhether to skip the 'add_correctors' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_correctors' task 
- dont_create_functionsFalseWhether to skip the 'add_function' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_function' task 
- dont_create_icsFalseWhether to skip the 'add_ic'/'add_fv_ic' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_ic'/'add_fv_ic' task 
- dont_create_kernelsFalseWhether to skip the 'add_kernel' task for each kernel typeDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_kernel' task for each kernel type 
- dont_create_materialsFalseWhether to skip the 'add_material' task for each material typeDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_material' task for each material type 
- dont_create_postprocessorsFalseWhether to skip the 'add_postprocessors' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_postprocessors' task 
- dont_create_solver_variablesFalseWhether to skip the 'add_variable' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_variable' task 
- dont_create_user_objectsFalseWhether to skip the 'add_user_object' task. This does not apply to UserObject derived classes being created on a different task (for example: postprocessors, VPPs, correctors)Default:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_user_object' task. This does not apply to UserObject derived classes being created on a different task (for example: postprocessors, VPPs, correctors) 
- dont_create_vectorpostprocessorsFalseWhether to skip the 'add_vectorpostprocessors' taskDefault:False C++ Type:bool Controllable:No Description:Whether to skip the 'add_vectorpostprocessors' task 
Reduce Physics Object Creation Parameters
- initial_from_file_timestepLATESTGives the time step number (or "LATEST") for which to read the Exodus solutionDefault:LATEST C++ Type:std::string Controllable:No Description:Gives the time step number (or "LATEST") for which to read the Exodus solution 
- initialize_variables_from_mesh_fileFalseDetermines if the variables that are added by the action are initializedfrom the mesh file (only for Exodus format)Default:False C++ Type:bool Controllable:No Description:Determines if the variables that are added by the action are initializedfrom the mesh file (only for Exodus format) 
Restart From Exodus Parameters
- preconditioningdefaultWhich preconditioning to use for this PhysicsDefault:default C++ Type:MooseEnum Controllable:No Description:Which preconditioning to use for this Physics