Define Multiplier Functions

Use the Multipliers tool to create, edit, and delete multiplier functions. Multiplier or ramp functions are used to multiply or ramp variables while defining boundaries, radiation, and mesh conditions.

Create Multiplier Functions

Use the Multipliers tool to create new multiplier functions.

  1. From the Flow ribbon, click the arrow next to the Setup tool group name, then select Multipliers.


    Figure 1.
    The Multiplier Library opens.
  2. Click to add a new multiplier.
    A multiplier creation dialog opens.
  3. Select a constant or varying multiplier type and input values.
    Option Description
    Constant Define a constant multiplying value.
    Piecewise linear, Piecewise Log Linear, Cubic Spline Use the table and the plot area.

    You can use existing pre-defined functions to populate the data then edit the data using the table or interactively with the plot.
    Sinusoidal Define frequency, amplitude, and phase.
    User Function Enter a function then select an argument type from the drop-down menu and input values in the table.
  4. Select a Variable, Evaluation method, and Filter.
  5. Close the dialog.
Once multipliers are defined, they can be applied to domains, boundaries, radiation, or motion definitions. Click in a dialog to select a multiplier. You can also have the option to create a new multiplier.


Figure 2.

Convert Pre-Defined Functions

When defining multipliers, you can use pre-defined functions to help populate table data.

Pre-defined functions are only available for varying multiplier types: Piecewise Linear, Piecewise Log Linear, and Cubic Spline.
  1. From the multiplier creation dialog, click the Function drop-down menu and select a function type.
    Step
    Sds
    Single Wave
    Oscillating
    Swept Sine
    Impulse
    Ramp
  2. Define the function parameters in the following ways:
    • Enter values in the text boxes.
    • Click and drag the grid lines in the plot area that correspond to the function parameters.
      The grid lines that can be manipulated appear darker and are highlighted when hovered over.


      Figure 3.
      Note: Individual points cannot be repositioned when manipulating pre-defined functions.
    • Below the plot area, choose a defined end time and output rate or input a value in the text box.
    The plot and the function parameters dynamically update to reflect any changes.
  3. Click Convert.
    The function data is converted to table format.

    Once converted, you can edit the points in the table or drag points on the graph to further refine the multiplier.

Edit Multiplier Functions

Use the Multipliers tool to edit existing multiplier functions.

  1. From the Flow ribbon, click the arrow next to the Setup tool group name, then select Multipliers.


    Figure 4.
    The Multiplier Library opens
  2. Right-click on a multiplier and select Edit.
    A multiplier creation dialog opens.
  3. Optional: Click the name in the top-left corner of the dialog to rename the multiplier.
    This can also be done by double-clicking on the Name field in the Multiplier Library.
  4. Edit the multiplier parameters.
  5. Close the dialog to return to the Multiplier Library.
Tip: Copy and paste the settings defined in one multiplier to another using the right-click context menu in the Multiplier Library.

Delete Multiplier Functions

Use the Multipliers tool to delete existing multiplier functions.

  1. From the Flow ribbon, click the arrow next to the Setup tool group name, then select Multipliers.


    Figure 5.
    The Multiplier Library opens
  2. Select the multiplier to delete.
  3. Click or right-click and select Delete.
Note: If a multiplier is assigned anywhere, you cannot delete it.