INSFVTKESourceSink

The object computes the turbulent source and sink term for the turbulent kinetic energy equation.

Two terms are computed destruction = ϵ\epsilon and production = GkG_k and the term ϵGk\epsilon - G_k is passed to the residual. A different treatment is used for the bulk and the near wall regions.

Bulk formulation:

The turbulent production GkG_k is modeled as:

Gk=μtS2,G_k = \mu_t S^2 \,,

where:

  • μt\mu_t is the turbulent dynamic viscosity,

  • SS is the shear strain tensor internal norm, defined as S=2S:SS = \sqrt{2\mathbf{S}:\mathbf{S}} with the shear strain tensor defined as S=12[u+(u)T]\mathbf{S} = \frac{1}{2} [\nabla \vec{u} + (\nabla \vec{u})^T].

The turbulent kinetic energy dissipation rate ϵ\epsilon is generally coming from a coupled transport equation for ϵ\epsilon. However, for canonical or measured cases, e.g., isotropic decaying turbulence, the user can utilize predefined fields through functors in MOOSE.

To avoid the overproduction of turbulent kinetic energy in stagnation zones \cite{durbin1996k}, a production limiter is imposed in relation to the dissipation using the formulation in \cite{menter1994two}:

Gk=min(Gk,CPLρϵ),G_k = min \left( G_k , C_{PL} \rho \epsilon \right) \,,

where:

  • CPLC_{PL} it the limiter constant, and set by default to a recommended value of 10 \cite{durbin1996k}.

Wall formulation:

All cells in contact with a boundary identified in the "walls" list are applied a different treatment for production and destruction. A different formulation is used for the sub-laminar and logarithmic boundary layers. The determination of whether the near-wall cell lies in the laminar or logarithmic region is performed via the non-dimensional wall distance y+y^+. The non-dimensional wall distance is defined as

y+=ρypuτμ,y^+ = \frac{\rho y_p u_{\tau}}{\mu} \,,

where:

  • ρ\rho is the density,

  • ypy_p is the distance to the wall to the centroid of the next-to-wall cell,

  • uτu_{\tau} is the friction velocity, defined as uτ=τwρu_{\tau} = \sqrt{\frac{\tau_w}{\rho}} with τw\tau_w the shear stress at the wall for which the condition is applied,

  • μ\mu is the dynamic molecular viscosity.

For every next-to-wall cell and every iteration step, y+y^+ is found via an incremental fixed-point search algorithm. The cells belonging to the sub-laminar boundary layers are defined as those for which y+<11.25y^+ < 11.25. The ones belonging to the logarithmic boundary layer are those for which y+11.25y^+ \ge 11.25. The imposed threshold of y+=11.25y^+ = 11.25 is given by the value of y+y^+ at which the sub-laminar and logarithmic boundary profiles intersect.

In the sub-laminar region production of turbulent kinetic energy is negligible, therefore, if y+<11.25y^+ \lt 11.25:

Gk=0.0,G_k = 0.0 \,,

In the logarithmic boundary layers the production term is no longer negligible and is defined as:

Gk=τwu=μwuCμ0.25(k)κyp,G_k = \tau_w ||\nabla \vec{u}|| = \mu_w ||\nabla \vec{u}|| \frac{ C_{\mu}^{0.25} \sqrt(k)}{\kappa y_p} \,,

where:

  • Cμ=0.09C_{\mu} = 0.09 is a closure parameter,

  • kk is the turbulent kinetic energy,

  • u||\nabla \vec{u}|| is the near wall velocity gradient norm, which is defined as u=(un^)n^||\nabla \vec{u}|| = (\nabla \vec{u} \cdot \hat{n}) \cdot \hat{n},

  • κ=0.41\kappa = 0.41 is the von Kármán constant.

The formulation assumes that the near wall value is already imposed in the μt\mu_t functor.

When solving a linear problem, instead of the nonlinear formulation, the production term is formulated as:

Gk=μwuCμ0.25kkoldκyp.G_k = \mu_w ||\nabla \vec{u}|| \frac{ C_{\mu}^{0.25} k}{\sqrt{k_{old}} \kappa y_p} \,.

where:

  • koldk_{old} is the value of the turbulent kinetic energy in the previous iteration.

Whether the linear or nonlinear formulation is used can be controlled by the "linearized_model" parameter.

For the destruction, formulation is different for the sub-laminar and logarithmic layers. For the sub-laminar layer, the destruction is defined as follows:

ϵ=2μkyp2.\epsilon = \frac{2 \mu k}{y_p ^2} \,.

For the logarithmic layer, the destruction is defined as follows:

ϵ=Cμ0.75ρk32κyp.\epsilon = C_{\mu}^{0.75} \frac{\rho k^{\frac{3}{2}}}{\kappa y_p} \,.

commentnote

When the wall treatment is specified in this kernel, any boundary condition for kk will be ignored. In other words, there is no need to impose boundary conditions for kk when the wall treatment is specified in his kernel.

commentnote

When using near-wall treatment, we assume that the μt\mu_t functor is computed by an object that performs near-wall treatment. Otherwise, the results obtained won't not physically correct

Input Parameters

  • epsilonCoupled turbulent kinetic energy dissipation rate. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled turbulent kinetic energy dissipation rate. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

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

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

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

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

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

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

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

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

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

  • uThe velocity in the x direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The velocity in the x direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • 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

Required Parameters

  • C_mu0.09Coupled turbulent kinetic energy closure.

    Default:0.09

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled turbulent kinetic energy closure.

  • C_pl10Production Limiter Constant Multiplier.

    Default:10

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Production Limiter Constant Multiplier.

  • blockThe list of blocks (ids or names) that this object will be applied

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The list of blocks (ids or names) that this object will be applied

  • linearized_modelTrueBoolean to determine if the problem should be use in a linear or nonlinear solve.

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Boolean to determine if the problem should be use in a linear or nonlinear solve.

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

  • vThe velocity in the y direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The velocity in the y direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • wThe velocity in the z direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

    C++ Type:MooseFunctorName

    Unit:(no unit assumed)

    Controllable:No

    Description:The velocity in the z direction. A functor is any of the following: a variable, a functor material property, a function, a post-processor, or a number.

  • wall_treatmentneqThe method used for computing the wall functions 'eq_newton', 'eq_incremental', 'eq_linearized', 'neq'

    Default:neq

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:eq_newton, eq_incremental, eq_linearized, neq

    Controllable:No

    Description:The method used for computing the wall functions 'eq_newton', 'eq_incremental', 'eq_linearized', 'neq'

  • wallsBoundaries that correspond to solid walls.

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Boundaries that correspond to solid walls.

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>

    Unit:(no unit assumed)

    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>

    Unit:(no unit assumed)

    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>

    Unit:(no unit assumed)

    Controllable:No

    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

    Unit:(no unit assumed)

    Options:nontime, system

    Controllable:No

    Description:The tag for the matrices this Kernel should fill

  • vector_tagsnontimeThe tag for the vectors this Kernel should fill

    Default:nontime

    C++ Type:MultiMooseEnum

    Unit:(no unit assumed)

    Options:nontime, time

    Controllable:No

    Description:The tag for the vectors this Kernel should fill

Tagging 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.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Unit:(no unit assumed)

    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

    Unit:(no unit assumed)

    Controllable:No

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

  • newton_solveFalseWhether a Newton nonlinear solve is being used

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether a Newton nonlinear solve is being used

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Unit:(no unit assumed)

    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

    Unit:(no unit assumed)

    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

  • ghost_layers2The number of layers of elements to ghost.

    Default:2

    C++ Type:unsigned short

    Unit:(no unit assumed)

    Controllable:No

    Description:The number of layers of elements to ghost.

  • use_point_neighborsFalseWhether to use point neighbors, which introduces additional ghosting to that used for simple face neighbors.

    Default:False

    C++ Type:bool

    Unit:(no unit assumed)

    Controllable:No

    Description:Whether to use point neighbors, which introduces additional ghosting to that used for simple face neighbors.

Parallel Ghosting Parameters