• InfoWorks WS Pro

Running a transient systems simulation

Run a transient systems simulation to detect potential problem areas due to transient pressures.

Tutorial resources

These downloadable resources will be used to complete this tutorial:


Step-by-step guide

InfoWorks WS Pro includes a transient systems (TS) simulation option that can indicate potential critical areas within the network due to transient pressures. The transient advisor results provide a qualitative estimate of the potential issues that you may wish to investigate further.

IMPORTANT: The results of a transient analysis are difficult to interpret, so you may wish to consult someone with expertise in this area.

  1. Open the network.
  2. From the Model Group window, expand the TS Model group.
  3. Open the TS Network and TS Control by double-clicking the TS Network, or by dragging and dropping it into the main window.

The InfoWorks WS Pro interface, with the TS Network active for this exercise.

To set the properties of the pump to represent a 5-second pump trip and need to account for the non-return nature of the pump station:

  1. Use the Find Network Objects tool to locate the pump station with asset ID “KCH2PMP”.

The Network Find dialog box, with the network and control for this exercise active, the asset ID inputted, and Select all objects found highlighted for selection.

  1. In the Tools toolbar, click Properties.
  2. Scroll down to Transient.
  3. Click the plus sign (+) to expand the Transient Page.
  4. Select the Enable Surge checkbox.
  5. Expand the Pump Change drop-down and select Trip.
  6. Set the Trip Time to 5 seconds.
  7. Next, set the NRV (non-return valve) Diameter to 50.8mm.
  8. Set the Loss Coefficient to 0.
  9. Enable Do Not Reopen the NRV.
  10. Set the NRV Response Time to 0.1 seconds.
  11. Commit changes to the database.

The Properties window, with the Transient parameters set for this exercise, and the TS Control shortcut menu expanded with Commit changes to database highlighted.

To run the TS simulation:

  1. Right-click Model Group.
  2. Select New > Run Group.
  3. Click OK.
  4. Right-click the new Run Group.
  5. Select New > Run.
  6. In the Schedule Hydraulic Run dialog box, enter “TS-Pump Trip” in the Title field.
  7. From the Model Group window, drag InfoWorks TS Network, InfoWorks TS Control, and Average Demand and drop them into the Network, Control, and Demand Diagram boxes.
  8. Select the box next to Experimental.
  9. In the Run Type group box, expand the drop-down.
  10. Select InfoWorks TS to open the InfoWorks TS Options dialog box.
  11. Set the Transient simulation start to 2 May 2022 at 06:00 and the Duration(s) to 30 seconds.
  12. Leave the remaining options as the defaults.
  13. Click OK.

The InfoWorks TS Options dialog box, with the parameters set for this exercise, and the Schedule Hydraulic Run dialog box open in the background, with the TS-Pump Trip run active.

  1. Back in the Schedule Hydraulic Run dialog box, at the bottom of the Run Parameters group box, expand the drop-down and select Simulation Options.
  2. Click the Options button next to it to open the Simulation Options window.
  3. In the Description column, locate the Advise on Hydraulic Transients option.
  4. In the same row, in the Default column, deselect the checkbox so that the Value column shows Yes.
  5. Click OK to close the window.

The Simulation Options dialog box, with the Advise on Hydraulic Transients option set active, its checkbox cleared and Yes showing as its Value.

  1. Click Save.
  2. Ensure that there are no ERRORS in the Parameters Setup Messages box.
  3. Click Run.

The Schedule Hydraulic Run dialog box, with the parameters set for this exercise.