Large Scale Interface Turbulence Damping Model Reference

In the vicinity of large scale interface, a boundary layer develops and the interface must be treated as a moving wall. The Large Scale Interface Turbulence Damping model achieves this by prescribing turbulence production and/or dissipation rate near the large scale interface.

Table 1. Large Scale Interface Turbulence Damping Model Reference
Theory	See Turbulence Damping.
Provided By	[phase interaction] > Models > Optional Models
Example Node Path	[phase interaction] > Models > Interface Turbulence Damping
Requires	Physics continuum selections: Material: Multiphase Multiphase Model: Eulerian Multiphase (EMP) (Automatically activates: Multiphase Interaction, Gradients.) Viscous Regime: Turbulent ( Phasic Turbulence or Mixture Turbulence) Phase selections: Turbulence: Reynolds-Averaged Navier-Stokes Reynolds-Averaged Turbulence: K-Epsilon Turbulence or K-Omega Turbulence A Multiple Flow Regime Topology phase interaction is required. Phase interaction selection: Optional Models: Large Scale Interface Turbulence Damping
Properties	None.
Activates	Model Controls	Primary Phase Turbulence Damping (for Phasic Turbulence) Secondary Phase Turbulence Damping (for Phasic Turbulence) Mixture Turbulence Damping (for Mixture Turbulence) See Primary/Secondary Phase Turbulence Damping and Mixture Damping Properties.

Primary/Secondary Phase Turbulence Damping and Mixture Damping Properties

The same properties are available for the Primary Phase Turbulence Damping node, the Secondary Phase Turbulence Damping node, and the Mixture Turbulence Damping node.

For a phase that has the K-Omega turbulence model activated, you can choose the turbulence damping method and the interface distance specification, you also set the Turbulence Damping Constant, Damping Calibration Factor and the Maximum Tangential Velocity. For a phase that has the K-Epsilon turbulence model activated, you can only set the Damping Calibration Factor and the Maximum Tangential Velocity.

K-Omega/K-Epsilon Parameters

Turbulence Damping Treatment

This property is available only when the corresponding phase has the K-Omega turbulence model activated. The available turbulence damping methods are:

Egorov—uses a symmetric damping procedure to model the interface as a moving wall for both of the phases in the interface region. This method is the default. See Egorov Turbulence Damping Treatment for the K-Omega Model
Wall Type—uses high Re wall treatment at near-interface cells to specify turbulence quantities directly. The cells that are detected by the Large Interface Detection model are classified as interface cells and a stencil is created for each large scale interface consisting a near wall cell on each side of the interface. The wall treatment is applied to these near wall cells for the respective phases. See Wall Type Turbulence Damping Treatment for the K-Omega and K-Epsilon Models.

Turbulence Damping Constant

This property is available only when the corresponding phase has the K-Omega turbulence model activated with the Egorov turbulence damping treatment.

Specifies the value B in Eqn. (2317). The default value is 500.0.

Damping Calibration Factor

This property is available for K-Epsilon turbulence, and K-Omega turbulence when the Wall Type turbulence damping treatment is selected.

Specifies the value C in Eqn. (2319) and Eqn. (2321) for for K-Omega and K-Epsilon, respectively. The default value is 1.0.

Interface Distance Specification

Available only when the corresponding phase has the K-Omega turbulence model activated.

The methodology for specifying the interface distance. The large interface distance is the distance between the interface and the cell centroid, normal to the interface.

Cell Volume

An approximation of the interface distance is derived from the cell volume ( $l_{d} = \sqrt[3]{Δ v}$ ).

This option is available only if the Egorov method is selected.
Geometric Reconstruction

Calculates the interface distance by performing a geometric reconstruction of the interface where the interface shape within the cell is approximated as a line-segment.

See Turbulence Damping. This method is the default.

Tangential Velocity

This property is available for K-Epsilon turbulence, and K-Omega turbulence when the Wall Type turbulence damping treatment is selected.

Specifies the value $u_{t, \max}$ for calculating $u_{t, \lim}$ in Eqn. (2320). The default value is 1.0 m/s.