Turbulent Dispersion Force Model Reference

Particles in a turbulent flow experience a greater level of dispersion than in a laminar flow. The Turbulent Dispersion Force model accounts for the interaction between the dispersed phase and the surrounding turbulent eddies.

Table 1. Turbulent Dispersion Force Model Reference
Theory See Turbulent Dispersion.
Provided By [phase interaction] > Models > Optional Models
Example Node Path [phase interaction] > Models > Turbulent Dispersion Force
Requires
Physics continuum selections:
  • Material: Multiphase
  • Multiphase Model: Eulerian Multiphase (EMP) (Automatically activates: Multiphase Interaction, Gradients.)
  • Viscous Regime: Turbulent

A Continuous-Dispersed Topology or Multiple Flow Regime Topology phase interaction is required.

Phase interaction selections:
  • Optional Models: Turbulent Dispersion Force (Automatically activates: Virtual Mass Coefficient.)

The Virtual Mass Coefficient model is required when you use the Turbulent Dispersion Force model because the virtual mass coefficient is used in the Inertial Correction and Tchen Correction methods for Turbulent Dispersion Force Prandtl Number. This model is also required so that the virtual mass coefficient becomes available for user modeling with the Field Function method.

See Virtual Mass Coefficient Model Reference.

Properties Key Property: Calibration Constant

See Turbulent Dispersion Force Properties.

Activates Model Controls

For a Continuous-Dispersed phase interaction:

Turbulent Dispersion Force Prandtl Number

For a Multiple Flow Regime phase interaction:

  • First Dispersed Regime Turbulent Dispersion Prandtl Number

  • Intermediate Regime Turbulent Dispersion Prandtl Number

  • Second Dispersed Regime Turbulent Dispersion Prandtl Number

See Turbulent Dispersion Force Prandtl Number Properties.

Field Functions See Turbulent Dispersion Force Field Functions.

Turbulent Dispersion Force Properties

Calibration Constant
C 0 in Eqn. (2024), with a default value of 1.
Use Volume Fraction Smoothing

Reduces numerical checkerboarding in the presence of dominant turbulent dispersion forces and hence improves convergence. This option does not affect the converged solution.

  • Activated

    Use smoothing.

  • Deactivated

    No smoothing, the default.

Use Tensorial Diffusivity

Where a Reynolds Stress model has been selected for the continuous phase, activating this option makes the simulations use an anisotropic model for turbulent dispersion (Eqn. (2025)). If this option is not active, or if a turbulence model based on the eddy viscosity hypothesis is selected for the continuous phase, then the simulation uses the isotropic model (Eqn. (2024)) instead.

Turbulent Dispersion Force Prandtl Number Properties

Dimensions
The dimensionality of the Prandtl number (read only).
Method
The method to use for specifying the Prandtl number, σ α in Eqn. (2027).
  • Constant
  • Field Function
  • Inertial Correction

    Recommended for large particles or bubbles.

  • Tchen Correction

    Recommended for small particles or bubbles.

Turbulent Dispersion Force Field Functions

For a Continuous-Dispersed phase interaction:

Turbulent Dispersion Prandtl Number of [phase interaction]

For a Multiple Flow Regime phase interaction:

First Dispersed Regime Turbulent Dispersion Prandtl Number of [phase interaction]
Intermediate Regime Turbulent Dispersion Prandtl Number of [phase interaction]
Second Dispersed Regime Turbulent Dispersion Prandtl Number of [phase interaction]