Navier Stokes Flow / WCNSLinearFVFlowPhysics

Define the Navier Stokes weakly-compressible equations with the linear solver implementation of the SIMPLE scheme

Equations

This Physics object creates the kernels and boundary conditions to solve the Navier Stokes equations for the flow using the SIMPLE algorithm. For regular flow in a non-porous medium:

ρv=0\nabla \cdot \rho \vec{v} = 0(ρvv)=(μ[v+vT])p+Fg\nabla \cdot (\rho \mathbf{v} \otimes \mathbf{v}) = \nabla \cdot \left(\mu \left[\nabla \mathbf{v}+\nabla \mathbf{v}^T\right]\right) - \nabla p + \mathbf{F}_g

where:

  • ρ\rho is the density

  • μ\mu is the dynamic viscosity

  • v\mathbf{v} is the velocity (non-porous flow)

  • pp is the pressure

  • Fg\mathbf{F}_g is the gravitational force

The kernels created for the momentum equation for free flow:

The kernels created for free flow for the pressure correction equation:

Automatically defined variables

The WCNSLinearFVFlowPhysics automatically sets up the variables which are necessary for the solution of a given problem. These variables can then be used to couple fluid flow simulations with other physics. The list of variable names commonly used in the action syntax is presented below:

For the default names of other variables used in this action, visit this site.

Coupling with other Physics

Coupling with other Physics has not been implemented for WCNSLinearFVFlowPhysics. Coupling can only be performed at the moment by leveraging MultiApps.

Input Parameters

  • blockBlocks (subdomains) that this Physics is active on.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Blocks (subdomains) that this Physics is active on.

  • compressibilityincompressibleCompressibility constraint for the Navier-Stokes equations.

    Default:incompressible

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:incompressible, weakly-compressible

    Controllable:No

    Description:Compressibility constraint for the Navier-Stokes equations.

  • fluid_temperature_variableIf supplied, the system checks for available fluid temperature variable. Otherwise, it is created within the action.

    C++ Type:NonlinearVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:If supplied, the system checks for available fluid temperature variable. Otherwise, it is created within the action.

  • flux_inlet_directionsThe directions which can be used to define the orientation of the flux with respect to the mesh. This can be used to define a flux which is incoming with an angle or to adjust the flux direction with respect to the normal. If the inlet surface is defined on an internal face, this is necessary to ensure the arbitrary orientation of the normal does not result in non-physical results.

    C++ Type:std::vector<libMesh::Point>

    Unit:(no unit assumed)

    Controllable:No

    Description:The directions which can be used to define the orientation of the flux with respect to the mesh. This can be used to define a flux which is incoming with an angle or to adjust the flux direction with respect to the normal. If the inlet surface is defined on an internal face, this is necessary to ensure the arbitrary orientation of the normal does not result in non-physical results.

  • flux_inlet_ppsThe name of the postprocessors which compute the mass flow/ velocity magnitude. Mainly used for coupling between different applications.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the postprocessors which compute the mass flow/ velocity magnitude. Mainly used for coupling between different applications.

  • include_deviatoric_stressFalseWhether to include the full expansion (the transposed term as well) of the stress tensor

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether to include the full expansion (the transposed term as well) of the stress tensor

  • orthogonality_correctionFalseWhether to use orthogonality correction

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether to use orthogonality correction

  • preconditioningnoneWhich preconditioning to use for this Physics

    Default:none

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:default, none

    Controllable:No

    Description:Which preconditioning to use for this Physics

  • transientsame_as_problemWhether the physics is to be solved as a transient

    Default:same_as_problem

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:true, false, same_as_problem

    Controllable:No

    Description:Whether the physics is to be solved as a transient

  • verboseFalseFlag to facilitate debugging a Physics

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Flag to facilitate debugging a Physics

Optional Parameters

  • 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

  • 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.

  • define_variablesTrueWhether to define variables if the variables with the specified names do not exist. Note that if the variables are defined externally from the Physics, the initial conditions will not be created in the Physics either.

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether to define variables if the variables with the specified names do not exist. Note that if the variables are defined externally from the Physics, the initial conditions will not be created in the Physics either.

  • ghost_layers1Number of layers of elements to ghost near process domain boundaries

    Default:1

    C++ Type:unsigned short

    Unit:(no unit assumed)

    Controllable:No

    Description:Number of layers of elements to ghost near process domain boundaries

  • 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.

Advanced Parameters

  • boussinesq_approximationFalseTrue to have Boussinesq approximation

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:True to have Boussinesq approximation

  • gravity0 0 0The gravitational acceleration vector.

    Default:0 0 0

    C++ Type:libMesh::VectorValue<double>

    Unit:(no unit assumed)

    Controllable:No

    Description:The gravitational acceleration vector.

  • ref_temperature273.15Value for reference temperature in case of Boussinesq approximation

    Default:273.15

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Value for reference temperature in case of Boussinesq approximation

Gravity Treatment Parameters

  • densityrhoThe name of the density. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    Default:rho

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the density. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • dynamic_viscositymuThe name of the dynamic viscosity. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    Default:mu

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the dynamic viscosity. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

Material Properties Parameters

  • friction_blocksThe blocks where the friction factors are applied to emulate flow resistances.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The blocks where the friction factors are applied to emulate flow resistances.

  • friction_coeffsThe friction coefficients for every item in 'friction_types'. Note that if 'porous_medium_treatment' is enabled, the coefficients already contain a velocity multiplier but they are not multiplied with density yet!

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The friction coefficients for every item in 'friction_types'. Note that if 'porous_medium_treatment' is enabled, the coefficients already contain a velocity multiplier but they are not multiplied with density yet!

  • friction_typesThe types of friction forces for every block in 'friction_blocks'.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The types of friction forces for every block in 'friction_blocks'.

  • standard_friction_formulationTrueFlag to enable the standard friction formulation or its alternative, which is a simplified version (see user documentation for PINSFVMomentumFriction).

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Flag to enable the standard friction formulation or its alternative, which is a simplified version (see user documentation for PINSFVMomentumFriction).

Friction Control Parameters

  • initial_from_file_timestepLATESTGives the time step number (or "LATEST") for which to read the Exodus solution

    Default:LATEST

    C++ Type:std::string

    Unit:(no unit assumed)

    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

    Unit:(no unit assumed)

    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

  • initial_pressure1e5The initial pressure, assumed constant everywhere

    Default:1e5

    C++ Type:FunctionName

    Unit:(no unit assumed)

    Controllable:No

    Description:The initial pressure, assumed constant everywhere

  • initial_velocity1e-15 1e-15 1e-15 The initial velocity, assumed constant everywhere

    Default:1e-15 1e-15 1e-15

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The initial velocity, assumed constant everywhere

  • pressure_variableIf supplied, the system checks for available pressure variable. Otherwise, it is created within the action.

    C++ Type:NonlinearVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:If supplied, the system checks for available pressure variable. Otherwise, it is created within the action.

  • velocity_variableIf supplied, the system checks for available velocity variables. Otherwise, they are created within the action.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:If supplied, the system checks for available velocity variables. Otherwise, they are created within the action.

Variables Parameters

  • inlet_boundariesNames of inlet boundaries

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Names of inlet boundaries

  • momentum_inlet_functorsFunctions for inlet boundary velocities or pressures (for fixed-pressure option). Provide a double vector where the leading dimension corresponds to the number of fixed-velocity and fixed-pressure entries in momentum_inlet_types and the second index runs either over dimensions for fixed-velocity boundaries or is a single function name for pressure inlets.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Functions for inlet boundary velocities or pressures (for fixed-pressure option). Provide a double vector where the leading dimension corresponds to the number of fixed-velocity and fixed-pressure entries in momentum_inlet_types and the second index runs either over dimensions for fixed-velocity boundaries or is a single function name for pressure inlets.

  • momentum_inlet_typesTypes of inlet boundaries for the momentum equation.

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:fixed-velocity, flux-velocity, flux-mass, fixed-pressure

    Controllable:No

    Description:Types of inlet boundaries for the momentum equation.

Inlet Boundary Conditions Parameters

  • momentum_advection_interpolationupwindThe numerical scheme to use for interpolating momentum/velocity, as an advected quantity, to the face.

    Default:upwind

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:average, upwind, sou, min_mod, vanLeer, quick, skewness-corrected

    Controllable:No

    Description:The numerical scheme to use for interpolating momentum/velocity, as an advected quantity, to the face.

  • pressure_two_term_bc_expansionTrueIf a two-term Taylor expansion is needed for the determination of the boundary valuesof the pressure.

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:If a two-term Taylor expansion is needed for the determination of the boundary valuesof the pressure.

Numerical Scheme Parameters

  • momentum_outlet_typesTypes of outlet boundaries for the momentum equation

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:fixed-pressure, zero-gradient, fixed-pressure-zero-gradient

    Controllable:No

    Description:Types of outlet boundaries for the momentum equation

  • outlet_boundariesNames of outlet boundaries

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Names of outlet boundaries

  • pressure_functorsFunctions for boundary pressures at outlets.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Functions for boundary pressures at outlets.

Outlet Boundary Conditions Parameters

  • momentum_wall_functorsFunctors for each component of the velocity value on walls. This is only necessary for the fixed-velocity momentum wall types.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Functors for each component of the velocity value on walls. This is only necessary for the fixed-velocity momentum wall types.

  • momentum_wall_typesTypes of wall boundaries for the momentum equation

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:symmetry, noslip, slip, wallfunction

    Controllable:No

    Description:Types of wall boundaries for the momentum equation

  • wall_boundariesNames of wall boundaries

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Names of wall boundaries

Wall Boundary Conditions Parameters

  • pin_pressureFalseSwitch to enable pressure shifting for incompressible simulations.

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Switch to enable pressure shifting for incompressible simulations.

  • pinned_pressure_point0 0 0The XYZ coordinates where pressure needs to be pinned for incompressible simulations.

    Default:0 0 0

    C++ Type:libMesh::Point

    Unit:(no unit assumed)

    Controllable:No

    Description:The XYZ coordinates where pressure needs to be pinned for incompressible simulations.

  • pinned_pressure_typeaverage-uoTypes for shifting (pinning) the pressure in case of incompressible simulations.

    Default:average-uo

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:average, point-value, average-uo, point-value-uo

    Controllable:No

    Description:Types for shifting (pinning) the pressure in case of incompressible simulations.

  • pinned_pressure_value1e5The value used for pinning the pressure (point value/domain average).

    Default:1e5

    C++ Type:PostprocessorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The value used for pinning the pressure (point value/domain average).

Incompressible Flow Pressure Constraint Parameters