flow360.KOmegaSST

class KOmegaSST

Bases: TurbulenceModelSolver

KOmegaSST class for setting up the turbulence solver based on the SST k-omega model.

Example

>>> fl.KOmegaSST(
...     absolute_tolerance=1e-10,
...     linear_solver=LinearSolver(max_iterations=25),
...     update_jacobian_frequency=2,
...     equation_evaluation_frequency=1,
... )

type_name: Literal['kOmegaSST'] = 'kOmegaSST'

modeling_constants: KOmegaSSTModelConstants = KOmegaSSTModelConstants(type_name='kOmegaSSTConsts', C_DES1=0.78, C_DES2=0.61, C_d1=20.0, C_d2=3.0, C_sigma_k1=0.85, C_sigma_k2=1.0, C_sigma_omega1=0.5, C_sigma_omega2=0.856, C_alpha1=0.31, C_beta1=0.075, C_beta2=0.0828, C_beta_star=0.09)

A KOmegaSSTModelConstants object containing the coefficients used in the SST k-omega model. For the default values used in Flow360, please refer to KOmegaSSTModelConstants.

CFL_multiplier: PositiveFloat = 2.0

Factor to the CFL definitions defined in the Time Stepping section.

Constraints:

• gt = 0

absolute_tolerance: PositiveFloat = 1e-08

Tolerance for the turbulence model residual, below which the solver progresses to the next physical step (unsteady) or completes the simulation (steady).

Constraints:

• gt = 0

equation_evaluation_frequency: PositiveInt = 4

Frequency at which to update the turbulence equation.

Constraints:

• gt = 0

DDES: bool = False

True enables Delayed Detached Eddy Simulation. Supported for both SpalartAllmaras and kOmegaSST turbulence models, with and without AmplificationFactorTransport transition model enabled.

grid_size_for_LES: Literal['maxEdgeLength', 'meanEdgeLength'] = 'maxEdgeLength'

Specifes the length used for the computation of LES length scale. The allowed inputs are maxEdgeLength and meanEdgeLength.

reconstruction_gradient_limiter: pd.confloat(ge=0, le=2) = 1.0

The strength of gradient limiter used in reconstruction of solution variables at the faces (specified in the range [0.0, 2.0]). 0.0 corresponds to setting the gradient equal to zero, and 2.0 means no limiting.

Constraints:

• ge = 0

• le = 2

quadratic_constitutive_relation: bool = False

Use quadratic constitutive relation for turbulence shear stress tensor instead of Boussinesq Approximation.

update_jacobian_frequency: PositiveInt = 4

Frequency at which the jacobian is updated.

Constraints:

• gt = 0

max_force_jac_update_physical_steps: NonNegativeInt = 0

For physical steps less than the input value, the jacobian matrix is updated every pseudo-step overriding the update_jacobian_frequency value.

Constraints:

• ge = 0

linear_solver: LinearSolver = LinearSolver(max_iterations=20, absolute_tolerance=None, relative_tolerance=None)

Linear solver settings, see LinearSolver documentation.

relative_tolerance: NonNegativeFloat = 0

Tolerance to the relative residual, below which the solver goes to the next physical step. Relative residual is defined as the ratio of the current pseudoStep’s residual to the maximum residual present in the first 10 pseudoSteps within the current physicalStep. NOTE: relativeTolerance is ignored in steady simulations and only absoluteTolerance is used as the convergence criterion.

Constraints:

• ge = 0

order_of_accuracy: Literal[1, 2] = 2

Order of accuracy in space.