Calculating a Pressure Drop

You can calculate the pressure drop on a pipe or a tube segment. The simulation is based on a Modelica model using the Modelica Standard Library.

For more information, see Dymola Behavior Modeling User's Guide.

Before you begin: Open a product containing a fluidic network.
  1. From the Fluid Design section of the action bar, click Pressure Drop Computation .
    The Piping/Tubing Calculator dialog box appears.
  2. Under Simulation type, select a type of study and a flow model:
    The available studies are the following:
    • Fixed mass flow rate
    • Fixed average velocity
    • Fixed volume flow rate
    • Range of mass flow rate
    • Range of average velocity
    • Range of volume flow rate

    Depending on the type of study you select, the appropriate parameters are displayed.

    The flow model is Detailed Pipe Flow by default. This value is the only one available.

  3. Select a pipe or tube segment in the 3D area.
    The Pipe 1, Inlet 1 and Outlet 1 boxes under Selection are automatically filled in. In the 3D area, the selected segment is highlighted in blue and two arrows appear on the ends of the segment, a green arrow for the inlet and a red arrow for the outlet. The green arrow shows the inlet and the red arrow shows the outlet. You can invert the inlet and outlet by clicking the double arrow next to the Inlet and Outlet boxes in the dialog box.
    Note: The ratio between the bend radius and the diameter of the pipe or tube must be between 0,5 and 3.
  4. Optional: To change your segment selection, click in the Pipe 1 box and select the segment of your choice.
    The Pipe 1, Inlet 1 and Outlet 1 boxes are updated.
  5. Under Simulation Parameters, select or type a value for the following parameters:
    • Medium: type of fluid used.
    • Mass flow rate or average velocity: this value must be positive to launch the simulation.
    • Ref. Pressure: reference pressure.
    • Roughness
  6. Under Advanced, set the following parameters:
    • Temperature
    • Gravity Axis: by default the axis is Z.
    Note: The units are defined in a CATPreferences file.
  7. Click Settings to set the compiler options.
    For more information, see Compiler.
  8. Click Custom Mediums... to create a medium with the parameters of your choice.
    A dialog box appears to let you define the properties of the new medium. Once created, it appears in the Medium list.
  9. Click Evaluate to start the simulation.
    If you have selected a fixed study, the results are displayed in a dialog box with precise values. If you have selected a range study, the results are displayed in a graph.
    Note: The Evaluate button is available only if the Mass flow rate, Average velocity, or Volume flow rate parameters are valuated.
  10. Optional: Change the parameters values and click Evaluate to start another simulation.
    A new Results dialog box is displayed and the Results dialog box of the first simulation is kept.