Define Free Surfaces

Use the Free Surface tool to specify free surfaces and imposes the appropriate nodal boundary condition on the mesh motion on those surfaces. Free surface properties are defined by surface tension and contact angle parameters.

  1. From the Motion ribbon, Constraints tools, click the Free Surface tool.


    Figure 1.
  2. Select surfaces.
  3. In the dialog, define a contact angle model type.
    Option Description
    None No model is used.
    Constant Enter a contact angle value.

    The contact angle is defined as the angle between the outward normal to the free surface and the outward normal to the side boundary. It may be any angle between zero and 180 degrees.
    Free Automatically computed. Used at inflow and outflow boundaries.
  4. Define a surface tension model type.
    Option Description
    None Surface tension is not modeled.
    Constant Enter a surface tension value.
    Piecewise Linear
    1. Click .
    2. Use the table and the plot area to create a data set.
    3. Close the dialog.
    Cubic Spline
    1. Click .
    2. Use the table and the plot area to create a data set.
    3. Close the dialog.
  5. Define the external pressure properties.
  6. From the guide bar, execute the command in the following ways:
    • Click to confirm your selection and remain in the tool.

      This allows you to continue creating instances and helps you visualize and edit instances with the legend.

    • Click to confirm your selection and exit the tool.