Setting Up the Volume of Fluid (VOF) Model

The Volume of Fluid (VOF) model is used for solving immiscible fluid problems.

To set up the Volume of Fluid (VOF) model:
  1. Right-click the Continua > [physics continuum] > Models node and select the following models:

    Group Box

    Model

    Space

    		Select one of:

    • Axisymmetric

    • Three Dimensional (required for Adaptive Mesh)

    • Two Dimensional

    Time

    		Select one of:
    • Steady
    • Implicit Unsteady
    • PISO Unsteady

      This option is appropriate in cases which have low coupling between the pressure, velocity, and volume fraction fields, or when the time-step is sufficiently small.

    Material

    Select one of :
    • Gas
    • Liquid
    • Multi-Component Gas
    • Multi-Component Liquid
    Multiphase

    Multiphase Interaction (selected automatically)

    Multiphase Model

    Volume of Fluid (VOF)

    See Flow Models Reference—Segregated Flow.

    Gradients, and Segregated Flow (selected automatically)
    Viscous Regime Select one of:

    • Laminar

    • Turbulent
    Optional Models

    If gravity forces influence the solution, select Gravity.

    To include thermal effects in your simulation, select Segregated Multiphase Temperature (required for Melting-Solidification).

    To modify the interface sharpness, select 体积分数重新初始化.

    To model surface gravity waves, select VOF Waves.
Proceed to set the Volume of Fluid (VOF) model properties.
  1. Select the [physics continuum] > Volume of Fluid (VOF) node and set the following properties:

    • Set Convection to either 1st-order, HRIC or Modified HRIC.

      This property sets the discretization scheme of the convective flux in the VOF transport equation. 1st-order is more stable but less accurate, whereas HRIC (High-Resolution Interface Capturing) and the Modified HRIC are more accurate but less stable.

    • If the simulation fluid is highly-compressible, set Face Density Reconstruction to 2nd-Order.

      This option is computationally more expensive, but offers a higher level of consistency between all transport equations.

      See Volume of Fluid (VOF) Properties.

      To maintain a sharp interface between the participating fluid phases, activate the HRIC convection and then set the HRIC properties.

      See HRIC Properties.

  2. (Optional) If you want to assess the quality, that is, the sharpness of the free surface:
    1. Select the Volume of Fluid (VOF) > Interface Detection node and set the following properties:
      Property Setting
      Sharp Interface Thickness Criterion Specify the number of cells up to which you want the interface to be considered as sharp.
      [Lower, Upper] Interface Volume Fraction Range Specify the lower and upper volume fraction limits that define a smeared cell.
      For more information, see Interface Detection Properties.
    2. To monitor the overall quality of the free surface within the domain or individual regions in the course of the simulation, right-click the Reports node and select New > Flow/Energy > Free Surface Quality, then create a monitor and plot from the report. For more information, see Free Surface Quality.